Poland could be the poster child for this trope. The only thing stopping him from being fabulously Camp Gay is the fact that his sexuality is never stated or touched upon.
Italy has a high, girly voice (said voice being by the same seiyuu as the below-mentioned Fai and sounding quite similar), a tendency to sleep naked with his male "friend" Germany, when growing up he wore a dress and was often mistaken for a girl, and when younger (Chibitalia) he had a romance going with the (male) Holy Roman Empire. He still likes pretty women.
England is very tsundere, and is the only one of the main eight characters to never show interest in women — when the cast is asked what kind of girl they would like, he's the only one who doesn't answer, albeit due to a "loss of time". England has also had Ship Tease with several male characters, mostly the implication that he has a crush on America. There's also when he infiltrates Italy and manages to blend right in....until he doesn't flirt with the girls. (Though compared to a lot of places in the world, Britain is a lot more reserved when it comes to hitting on people, regardless of gender.)Plus he does show interest in Hungary in the anime dub.
Germany, another tsundere, is in love with Italy, and the fandom often interprets Buon San Valentino as Germany's Coming-Out Story. However, it's possible Germany is sexually attracted to women as well. To make matters more confusing, he is extremely awkward when talking with women or talking about women, which could be interpreted either way.
Russia is often shown blushing, giggling, winking, giving off a pink flowery aura, and sending "pressure" in the form of little pink hearts. He is implied to have crushes on at least three male characters, especially Lithuania and China. He also greets men with a kiss on the lips, but this is only because of his cultural traditions. Lampshaded by America, who declares Russia is a "bad guy" for this greeting, implying Russia may be invoking the Depraved Homosexual or Depraved Bisexual (and Russia "offers" to "make his gums bleed" after he says this). Lastly, there's that he refuses to marry Belarus, the only person actually willing to "become one" with him, even though he acknowledges she's a very beautiful girl...but this could EASILY be because she's even more mentally unstable than him, and his own sister.
Azumanga Daioh: The only reason Kaorin's orientation is ambiguous, is because it was never confirmed whether she's actually in love with Sakaki, or simply fangirling really, REALLY, hard over her. The closest the series comes to addressing the issue was when Osaka asked Kaorin if she was gay, in the "10th Anniversary Omnibus". She tells Osaka that the correct term is "lesbian," then says her attraction to Sakaki is "teenage thing"; adding she wouldn't mind if Sakaki were a guy.
Alois Trancy in the second season of the anime. He alternates between being Ax-Crazy and sweet and cheerful, basically flirts with Sebastian via leaning into him and pronouncing that he "smells good", is very attached to his butler Claude, treats his one female maidservant like absolute crap (he stabs out her eye with his fingers just for looking at him and later mocks her for it), dresses and acts very effeminately and flamboyantly and has a girlish face. Well, he was ambiguous until episode 5 where he outright flirted with Ciel, licked his ear, and stated that he "wants" him. And in episode 11 when he tells Claude "I wanted your love."
Also, Finny of Ciel's household staff: girly looks, wears barrettes in his hair, Keet, a bit of a crybaby, and tends to go into fanboy mode over Sebastian.
And Claude. It becomes painstakingly obvious after he brainwashes Ciel, though maybe he just really wanted Ciel's soul...
Sebastian, believe it or not. Exhibit A. Stilettos. Exhibit B. The way he stands and walks, particularly prominent in the first couple of volumes. Exhibit C. Doesn't he say he finds Ash more attractive than Angela? Exhibit D. And, of course, fighting over Ciel with Claude, which leads to both Alois and Grell implying that he's in love with Ciel. Sebastian doesn't deny it, and, in fact, agrees while fighting Claude in episode... 10? That he's not fighting for Ciel's soul...
Creed from Black Cat is never explicitly stated outright to be gay. However, pretty much every single character in the series notices his romantic obsession with Train (other than Train himself). He dresses in very flamboyant, feathery clothing, and is constantly seen with roses (he has a freakin' bath filled with them!). He also seems rather resentful and angry at most of the females in the series.
The true nature of Sui-Feng's attachment to her mentor, Yoruichi, and her sexuality, in general, is an often debated subject. Many believe that she's in love with Yoruichi and cite her emotional breakdown at the end of their fight, along with the time she tried to take pictures of Yoruichi nakednote as her part of a project for the Shinigami Womens Association as evidence. Others dismiss it as Sui-Feng either fangirling over her, or feel she only looks up to Yoruichi as a 'big sister' figure (especially those who ship Yoruichi with Urahara). Either way, the anime team ran away with the subtext, to point of it being 'writing on the wall'.
Amongst the hollows, there is actor-wannabe, pink-haired, flamboyantSzayel Aporro Granz who becomes even more bishonen when he releases his sword, named Fornicarás (kanji: 'evil promiscuous queen/princess', Spanish: 'you will fornicate'), which he's also willing to deep-throat. His fights are accompanied by lewd, disturbing comments regarding the sexiness of his opponents and whether or not they're his type and when his clothes are damaged, he will stop fighting to get changed before continuing. He'll even use his cloning attack to give his opponents fashion make-overs.
In the original Bubblegum Crisis, Daley is openly gay, and would occasionally hit on his partner Leon McNichol in order to tease him.
Daley: You're too tense, Leon. We could get a hotel room together. Leon:(dismissive) Yeah, sure, Daley, just you and me.
Daley Wong and Linna Yamazaki from Bubblegum Crisis Tokyo 2040 share both similar backgrounds and extremely ambiguous sexuality, though nothing is ever admitted outright. Linna's reaction to the resident biker chick and bad girl getting a boyfriend is telling enough however, as is the fact that she spends the next couple of episodes moping about it. Poor Linna...
Koushaku Chouno, better known as Papillon, from Busou Renkin. He dresses in a flamboyant outfit including speedos and a distinctive butterfly mask, and he certainly has a lot of Foe Yay with Kazuki.
Lloyd Asplund is certainly mechasexual and Prince Schneizel is more ambiguous. His Bishounen advisor Kanon lampshades both in R2 09. He likes talking about love for a war advisor, apparently.
Kanon himself, who is quite pretty and expresses more concern for Schneizel than an advisor should for a boss. Side materials state that he's a crossdresser who had a hard time getting a job until Schneizel hired him for his talents and didn't mind his peculiar tastes.
Rolo in the anime. While he states that he sees Lelouch as a brother, there's some scenes where it seems more like he's in love with him. This is to the point where many fans saw his murdering Lelouch's girlfriend Shirley and his intended murdering of Nunnally, Lelouch's sister, as a case of Murder the Hypotenuse.
L. OK, so he does watch footage of Misa Amane strapped up against a board for a long time and does confess "I could actually fall for you" to her, but that doesn't stop him handcuffing himself to Light, as said before, and Light is the only character aside from Watari to whom he gives his 'phone number, he also had 3D art done on his nails, cross dressed twice in the "L: change the world" novel, even flirting with another male during it (though this could have been him just playing up the part ) not to mention his reaction to when Maki is kidnapped in the novel seems very reminiscent of a scared parent/mother
Near takes all the Foe Yay Light had with L to a creepy, rape-y, one sided extreme. He calls Light a lot and then hangs up without talking, pulls... odd faces when thinking of Light and in the manga it's revealed that Near didn't entirely want to kill Light, he wanted to keep him. And that's before we even get onto the Foe Yay chemistry that is more commonly interpreted between him and Mello.
Mello takes this trope so far as to be mistaken for a girl by a lot of readers/viewers until he is referred to as a "he" by other characters. He does not, like the other senior Mafia men, cuddle up with girls, dresses in tight leather long before he rides a motorbike for the first time in the series, has a VERY girly fur-lined coat, dons black lipstick and nail polish, ignores Hal Lidner's coquetry when she talks to him from her shower, licks chocolate bars suggestively in the company of other men, and lives with Ambiguously Biloose-cannon geek Matt in a house full of mannequins. He also seems unenthused when Matt points out that switching jobs would mean getting to spy on a cute girl (Misa.) Did we miss anything?
The elegant, well-manicured, immaculately-dressed and long-haired Yotsuba employee Reiji Namikawa. While almost all the other businessmen are either cuddling up with Misa's modelling friends or having a drink in her flat, he's busy looking at the artwork. Oh, and he wears a silver heart-shaped ring.
Rem's strange (and for a Shinigami, highly unusual and controversial) relationship with Misa Amane. (She says it's platonic, but who knows?) She also dies for her to rescue her and keeps Light alive just to keep her happy. That's some serious platonism!
Sayu, Light's little sister, is Ambiguously Lesbian- she first says that she "doesn't want a boyfriend." Then she exclaims that Misa is "my type!" And she smiles when leafing through one of Light's magazines. The ambiguity here is that she does fangirl over Hideki Ryuga (the pop star), so she might be Bi the Way if the fangirling is sexual in nature.
Yukio Oikawa in Digimon Adventure 02 wears a purple trenchcoat, and his entire motivation is his suspiciously obsessive friendship with his late childhood bud, Hiroki Hida.
D.Gray-Man has Kanda, who has an easy-to-provoke personality, a Bishōnen design, takes a lot of care of his long hair, and has an apparent lack of interest in any romance. Ironically, in later chapters it seems almost certain that he isn't gay after all, and in a Fourth-Wall Mail Slot interview Allen speculates that Kanda has no romantic interest in anything except Mugen, his sword.
General Blue in early parts of Dragon Ball. He is known to find women disgusting, Bulma and Krillin come right out and call him gay but he strenuously denies it, and barely an episode before he gets a bridge dropped on him, he's revealed to be a paedophile.
Dragon Ball Z has Zarbon, who has an extremely feminine face, keeps his hair in a long, loose braid, and wears lots of jewelry, not to mention shiny black thigh-high boots. He's also apparently rather obsessed with his appearance. Frieza is questionable as well, having extremely feminine mannerisms in the Japanese and a female voice in the dub (though changed as of Dragon Ball Kai, it still sounds quite feminine).
Goten and Trunks have been very tight friends literally their entire lives and, as teenagers, quite often spill over into Ho Yay. Trunks even shows no interest in women, and his mother went to the extreme of putting him in a office building shaped like a penis and filling it with hot women; he seems outright intimidated by both. Whether their being Fusion Dance partners makes this better or worse is debatable. In the second Dragon Ball GT ending, it begins with all the various couples being shown together: Goku and Chi-Chi, Gohan and Videl, Vegeta and Bulma, Krillin and Eighteen... and then cuts right to Trunks and Goten walking along, in the same style. Apparently the creators consider them "life partners" after one fashion or another.
At the end of Dragon Ball Z, when the Z fighters are competing in the tournament, Trunks is paired with a leather-bound muscle man who blows him a kiss and makes a comment to the effect of "Oh, I got the cute one."
Whis is campy, feminine, and blushes and smiles when his male boss accidentally flashes him in the third episode of Dragon Ball Super.
Kale the Legendary Super Saiyan of Universe 6 is implied to have a romantic crush on her boss Caulifla, the reason for her transformation is she believes Caulifla is in a relationship with Cabba, a male Saiyan and tries to kill him, once she assures her that she has no interest in Cabba only then does she calm down.
Kazuki of Fafner in the Azure: Dead Aggressor certainly qualifies. At least three girls have fallen in love with him, and he's either oblivious to their feelings or he knows and is completely uninterested. Then there's his utter devotion to Soushi, and the show makes sure to let the viewers know that they are the most important person to each other. He even vows to wait forever for Soushi to return at the end of the first season, and flies into a rage during the movie when Festum show up instead.
Fairy Tail has several examples - Freed Justine, Kagura Mikazuchi, and Cana. Freed hero-worships Laxus while Kagura looks up to Erza as a big sister, but at times, it seems like they have crushes on their respective idols (not helped by Kagura kissing Kagura on the lips and the anime Flanderizing Freed to make him wonder what Laxus would do before making any decision). Meanwhile, Cana has a habit of feeling up just about any attractive woman in later chapters (her most common target being Lucy).
Free!: Almost all the major characters are males show show zero interest in girls romantically and have very VERY intense friendships with at least one other male character.
Ayame Sohma from Fruits Basket. Long, feminine hair; feminine clothing; has been seen wearing an actual dress. He acts rather romantic and melodramatic, and his voice (at least in the dub) is... well... stereotypically gay. He and Shigure hit on each other with alarming regularity. And yet, after all this, he's a totally straight pervert who is revealed to be dating his (female) shop assistant, Mine. Even Ayame's American voice actor basically said in the most polite way he could that he didn't want to portray Ayame as a Camp Gay stereotype because he didn't want to be offensive. There's also that one scene where Kyou wakes up to find Ayame sleeping next to him in bed. He goes into a shocked state and Ayame mumbles "I'm still sleepy", grabs Kyou and tries to cuddle with him. We then see him covered in bandages from after Kyou beat the crap out of him and Ayame states he snuck into Kyou's room because Yuki had locked him out of his room when Ayame tried to sneak in.
Major Alex Louis Armstrong. He's never seen with any women, but this isn't a romance-heavy series, so that's not a strong indication. That said, a lot of his character traits—strong emotions and a preoccupation with bodybuilding and male beauty—fit a lot of Japanese stereotypes about gay men.
Garfiel from the manga and Brotherhood anime, the only reason why he isn't officially acknowledged as homo/bisexual is because the series doesn't state that directly.
Everyone in Gankutsuou, except Eugenie Danglars who is unambiguously straight. Extremely ironic, considering that she is as unambiguously lesbian in the original novel as 19th century literature could hint.
Kazuki from Get Backers. He was raised to be like a woman, he looks like a woman, he has long flowing hair, he is always surrounded by men, and Ban jokes about him and Juubei being like a married couple. He did show interest in one girl, but she looks like a boy and is actually a computerized being. He has never said a word about marrying and having children, even though he's the heir to the Fuuchouin clan and all its associated combat arts.
Bio Booster Armor Guyver has it's fair share of moments.
Tetsurō Segawa has subtle hints of being possibly gay towards his Bromance, Sho Fukamachi. His sister Mitzuki has taken various opportunities to paint them in such light when catching them in moments odd moments such as holding hands with Sho when the two were reaffirming their resolve and friendship. To top it off, he is never seen hitting on women, never flinching or startled when a naked Sho pops up unexpected. Such as when in the manga a Sho clone pops up and he comments on why he's naked due to the heat, and later when being busted out of a prison cell in the anime. During the final episode of anime, he encourages and pushes his sister to greet a long thought dead Sho, only for Natski to ask her why he wont himself, which causes him to blush in embarrassment.
The evil Chronos organization is nearly an exclusively male operated with male exclusive male membership in high ranks and troops. This has led to some ambiguity amongst their leaders and ranks. Supreme leader Archanfel has a girly elfish appearance, and later ends up having a shared mind with and mutual loyalty to fellow Zoalord Imurikum. Imurikum in turn is often shown carrying a Archanfel in his arms. The "Hyper Zoanoid Team Five" members have a big deal of loyalty to one another, but Elagen and Zx-Tole are portrayed in the OVA to a high degree of this trope with lines such as "You have to hold on, I need your strength, I need you!" and "Oh, I'll do anything for you Elegan!".
Itsuki Koizumi from Haruhi Suzumiya seems to like invading the main male character's personal space a little too much in the anime, and in the novels especially he makes it quite clear that he trusts and likes Kyon. He claims to act the way he does because Haruhi expects it and would make it real if he didn't, which would be a plausible explanation if he actually did so while Haruhi is watching. Also, in the 4th novel his alternate universe self admits to having a crush on Haruhi, but this isn't brought up in the main storyline - although many of his actions and words towards Haruhi, especially his constant claiming of being "the expert of her heart" imply some secret affection for her. Whatever the case may be, Itsuki's bond with Kyon could be seen as a fumbled attempt at a bromance or an actual romance slowly developing. Played for Laughs in Haruhi-chan, in which Itsuki makes blatant innuendos towards Kyon with no indication whether or not he's joking. And then there's the time when Kyon suddenly confesses his love to Itsuki. Cue the latter having the most G-rated possible depiction of an orgasm.
Father Jelice Bryah of Hatenkou Yuugi. Lampshaded by Rahzel "I don't recall coming out of some queer's stomach." (She said that because he was trying to be her father, but given the idiot of a dad she has, he is definitely a huge improvement.)
Here Is Greenwood: Kazuhiro Hasukawa, the older brother of main character Kazuya. Has a rather bishounen look to him and the rumors fly about his sexual orientation (he's the nurse in an all-male school). But then again, he's also Happily Married (and the wife is just another of the points of contention the brothers).
Schrodinger, from Hellsing. The flouncy, feminine Cat Boy evades this list no longer.
Rika and Satoko from Higurashi: When They Cry. Yes they're both approximately nine years old but their behavior, especially Rika's, is a bit suspicious, especially in the sound novels and manga. They have a very close friendship to the point where Satoko is a Living Emotional Crutch to Rika. In one arc Rika tried to kill herself in order to not see Satoko be abused in that universe. Rika and Hanyuu also looked like they were going to kiss in the intro to Kai. Bernkastel from Umineko: When They Cry is an expy of Rika, though she is implied to be an incarnation of her, and is in a relationship with another girl. Still, there are some implications that Rika might have a Precocious Crush on Akasaka and Keiichi, and there are a few jokes implying she might like boys, which also makes her lean on Ambiguously Bi.
Nanase from Honey Hunt is more than a little of this with his feminine looks, long hair always in a ponytail, skill at housekeeping and cooking meals, and pretty much acting like a nagging wife to his friend Mizorogi. At the same time he is also studying to be a make-up artist and hair stylist at a technical school. This is confirmed to be true in Chapter 21 where he outright admits to Yura that he's gay and in love with Mizorogi.
Jakotsu, who hits on pretty much every male character he comes into contact with (except Bankotsu), and has an unwanted attraction to Inuyasha, to the point where, in his sadistic version of love, tries to torture him to death because of it. After The Reveal that Jakotsu was the only completely loyal member of the Band of Seven, Bankostu shared a bubblyHeadbutt of Love with him.
Jaken started following Sesshomaru because he thought Sesshoumaru was beautiful. This is anime filler only and never happened in the manga.
Izetta and Finé the leading ladies of Izetta: The Last Witch have shown no interest in men and share great affection towards each other due to their history as childhood friends. Izetta shows strong devotion to Finé and is willing to break her taboo openly using magic to protect her while Finé at one point called Izetta, 'My White Witch'. Notably, prior to their reunion in the first episode, Finé dreams of her first meeting with Izetta and thinks about her a few times before offering herself up for a political marriage she previously declined.
Otohiko from Kamisama Kiss. He's an all around pretty boy that flirts with both men and women. He dresses in a stereotypically gay fashion (he even has a biohazard suit decked out in flowers) and his familiars are show-dogs with a heart shaped collars. Nanami even calls him a homosexual when they first meet but his actually sexual orientation has yet to have been revealed.
Kamui Den: Nowhere more ambiguously that with Ryunoshin and his young charge Miyagi Onya. Initially, the latter approaches Ryunoshin requesting that he become his "nenja" (a kind of mentor figure, but like the erastes of ancient Greece, with strong gay overtones). Ryunoshin says he has no interest in "shudo" (male pederasty), but recognizing the young man's purity of heart, accepts his request to form a special bond (chigiri) together. Of course, Shirato had to go and muddy the waters further by saying in a recap, that the two characters shared a bond of "shudo," which all but explictly labels them as gay lovers. Certain characters within the manga also seem to think their relationship swings this way. As they are never shown engaing in anything beyond mildly affectionate behaviour, it would seem they are in a platonic gay relationship...maybe.
Touko from Kara no Kyoukai blatantly flirts with Shiki, calling her 'a cute young lady along her line of fancy' the first time they meet. And then we have Word of God stating that the first thing she does upon activating her Body Backup Drive is hunt for pretty girls.
There's no doubt that Tomari from Kashimashi: Girl Meets Girl likes girls considering she is a love interest in a Yuri Genre manga. The question is "Did she like Hazumu when she was a boy?" She didn't seem to however there isn't much shown of their relationship pre-genderbend.
Ryuko shows no interest in boys throughout the series. She instead has a close bond with Mako and the series ends with them going on a date, though whether it's romantic or platonic is left vague especially since they meet up with Ryuko's sister and hang out with her.
As mentioned, Mako. She gets a nosebleed due to Ryuko and is quite close to her, even kissing her, however it's just ambiguous enough to call it 'simply humor' or she is really in love with Ryuko. She has some Ship Tease with Gamagoori and her though, and the above-mentioned date scene implies he is going to confess to her, but there's no word on her feelings for him.
Nonon Jakuzure. There is only one person she's nice to, Satsuki, and uses honorofics and phrases that would otherwise be inappropriate for her level on the totem pole.
Escargon from the Kirbyanime. It's pretty clear by episode 55 that he's in love with Dedede; he even uses "aishiteru" in his song at the beginning of the episode, and it's known that "aishiteru" is a stronger way of telling someone you love them. He even gets all flustered when he finds out Dedede heard the entire song. In the English dub, he was voiced with an impression of famous Transparent Closet actor Paul Lynde.
Miki from Life, and by extent Ayumu too. Their bond can be described as being stronger than a normal friendship but it's not exactly romance either. Apparently Ayumu liked a boy in middle school but she's shown no interest in boys in high school (though she has good reason not to with all the trouble she's been having). Ayumu falls for a boy by the end of the manga and Miki said she has a lover in her hometown though..
Konata of Lucky Star. Holy crap, you could write a book about this. Her room is covered in posters and figurines of moe girls, she talks about Miyuki's breasts (in a joking manner?), she is obsessed with adult dating games (but girls like those too... right?). She seems to have massive picture archives of moe girls classified into different fetishes on her computer, seeming to include pornographic images as is hinted at in one episode. She definitely admires the female form. She and Kagami seem entangled in some sort of love-hatequasi-romantic relationship. Konata, after Kagami give up her seat to her at a concert, seemingly touched remarks, "What is this feeling?" Konata seems to have only ever had female friends despite having interests which should win her plenty of male attention. On the other hand, Konata enjoys working at a Cosplay Café where she claims to enjoy the attention of the male customers whom she says are "kind of like" her boyfriends. She also seems to mention wanting a boyfriend (maybe? hard to sort out the exact words she used. might've been "lover". It was more of a daydream thing anyway where she imagined herself as several Da Capo characters before being swept off her feet by a bishounen [and therefore ambiguously male] version of herself). She also commented that she doesn't really like giant robot shows for the action but just thinks the bishi characters are hot. Whether she's talking about the bishounen or bishoujo character is not clear, though, as she seems to be watching Code Geass when she makes the comment.
Speaking of "knife edge between subtext and text", Lyrical Nanoha has the ever-popular Nanoha and Fate, who did all that Madoka and Homura did and more, outright adopting a child together. Again the staff love heaping on the Ship Tease, and there's semi-official Word of Gay from their voice actors, but explicit confirmation seems forever out of reach.
In chapter 336 where Fate says "He (Negi) already belongs to me. Give up." and the end of the chapter reads "The strongest love (?) rival appears."
While Setsuna's Bodyguard Crush on Konoka can be seen from space, Konoka herself is far less definite, and whether she just liked to tease Setsuna or genuinely returned her feelings continued to be a mystery. At the very least they get a lot of romantic/sexual moments together, and the epilogue heavily implies they married each other.
Their pactio kiss lasted much longer than it needed to, and Konoka only broke it off because Setsuna needed to breathe. Some took that scene as confirmation.
Though there's been ample amounts of subtext between Yuuka and Takaki, only the latter has been confirmed to be lesbian. Still, it's been implied that Yuuka may have feelings for her, if they're not already involved. They're almost always together, including when they arrived for the group's vacation to Okino Island, as if they were a couple. She also agreed with Uruchi, when the girls were discussing the kinds of guys they liked:
Uruchi:(while drunk) "I think real love isn't restricted to just having relationships withMEN!!"
During the flashback in chapter 48, Yuuka referred to Takaki as, "her important person", and the chapter 45 preface page shows them spooning together while engaged in foreplay. But the page caption says the scene has nothing to do with the actual story and is merely for fanservice. Yet, chapter 57 begins with a similar scene, which has Yuuka "healing"her.
Maria-sama ga Miteru: Essentially all of the girls. It's even more blatant with the original light novels as they go in-depth into the characters' thoughts. The characters have heavy levels of Homoerotic Subtext and it's the most famous Yuri Genre series but there isn't actually any confirmed romance between the characters.
Miss Kobayashi's Dragon Maid: Where Kobayashi's maid obsession ends and interest in girls begins is anyone's guess. The only times Kobayashi is shown having sexual interest in Tohru are when Kobayashi first saw Tohru transform from dragon into dragon-girl during their first drunk encounter in manga chapter 32/anime episode 12, where she was amazed how big Tohru's boobs were and wanted to fondle them, and after Ilulu switches her genitals against her will in the manga. Plus, besides Tohru, the only other people who are romantically interested in her are all female; and her male best friend, Takiya, is just her platonic best friend, nothing more.
Moonlight Ladys Io Azuma: Disappointed his cousin by growing up to be a "pretty boy" instead of a "hunk", really into J-Dramas, somewhat flighty, seems to polish his nails...unfortunately, nothing keeps him from being a pretty boy. Averted in the visual novel, where he is the Gay Option.
Zelik Lindemann and Silas Edwards in Mother Keeper come off as this way. Silas even seems to get slightly flirty with Zelik at one point.
My Hero Academia has a very subtle example, with Kirishima. It's stated that his favorite thing is "Manly Guys", which by itself is already pretty complicated. He shows no interest overall in any girl, but the amount of time he spends talking with or about Bakugou, besides his fight to convince everybody to help rescue him, even more than Midoriya, who is his childhood friend, make it sound like a crush. In recent Halloween art for "My Hero Academia Smash!!!", he is seen dressed as Little Red Riding Hood gleefully running from a half-naked Bakugou. At this point, if Kirishima isn't gay, it might just cause a bit of an uproar.
Madara Uchiha's obsession with Hashirama is well established, and that was before it was revealed that the Sharingan is activated by a loss of love, and Madara's was activated when he broke off his friendship with Hashirama...
Gaara shows no interest in the fangirls he gains following the Time Skip and has a Ho Yay filled relationship with Naruto. In particular in Chapter 678 when everyone is trapped inside Infinite Tsukuyomi, most of them dreamed about being with their Love Interest. Gaara dreamed about his family and Naruto. Also, Gaara's page on the Naruto Wiki gives us this gem under his personality section:
Gaara eventually formed a close friendship with Naruto, viewing the Kohoha ninja as his first true friend, and became very loyal to his decisions, and protective over him as a companion. Gaara also came to view meeting Naruto as the greatest event of his life and believed any price, even the painful life of a jinchūriki was worth the experience. Gaara even forgave Shukaku for his miserable childhood, claiming that it was only because of such a life that he was able to meet Naruto.
Kaworu Nagisa's behavior towards Shinji (who is himself Ambiguously Bi) and their interactions have been hotly debated since the show aired. A Homoerotic Subtext clearly exists, and is carried through to both Alternate Continuity works and some official artwork, but it's never made clear whether this is all there is or if more layers exist. Shinji, being so starved for affection, might see Kaworu as a parental figure or some other source of familial intimacy. On the other side, there's the possibility that familial and sexual affection may not be mutually exclusive for Shinji due to his desperation and traumatic upbringing. There are also arguments that Kaworu is just a Fish out of Water and does not realize that he's making suggestive comments, or that human sexuality is completely irrelevant to him since he's an Angel. In Rebuild of Evangelion 1.0, Kaworu awakens on the moon to promptly say "I'm looking forward to knowing you, Shinji Ikari." As lampshaded with many lulz by the fansubbing group, the Japanese word used can mean "to know in the biblical sense". And right after that he says he's gonna make Shinji "happy" this time... Approximately half of Rebuild 3.0 is devoted to Kaworu and Shinji's budding relationship before Kaworu is horribly killed. Kaworu describing them playing the piano together like they're having sex isn't even the gayest thing he does. It doesn't help that his original English voice actor had a slight lisp, an old stereotype of gay men. Whether this was done on purpose or not is unknown.
The manga mostly averts this, however, at least from Shinji's side; as he's creeped out by Kaworu's tendency to invade his personal space and tries to stay away from him as much as he can. In vol. 10, Kaworu uses a kiss to stop Shinji from hyperventilating during a nightmare, and makes advances toward Shinji which he flatly refuses. He later leaves Kaworu's apartment with very little in the way of a good-bye, which upsets Kaworu, although after Kaworu's death, he admits to himself that despite the way he acted, he was attracted to Kaworu, even though he knew he shouldn't like a boy like that.
Nyan Koi!: Junpei's friend Haruhiko, at least in his mannerisms. He's been known to buy eroge manga and was the one to start peeping on the girls during a Furo Scene. However, he was all-too-willing to wear the maid outfit during the school festival...
Cross-dressing ballerina kick-ologist Mr. 2 Bon Clay is about as ambiguous as they come. To the point where it's his catchphrase.
Nami shows little to no interest in men, and comments on the sex appeal of Kalifa during their fight. She also has a Romantic Two-Girl Friendship with Vivi, and they're shown sleeping against each other's shoulders in an opening.
Kyoya, and Tamaki to an extent. They give backrubs and call each other "mommy" and "daddy". Tamaki may be more along the lines of Ambiguously Bi given how he seems to genuinely enjoy female company, but Kyoya never displays any genuine interest in the club's customers beyond what he can get them to buy. When Tamaki calls the rest of the host club (other than Haruhi) the homosexual supporting cast, Kyoya is annoyed. However, he's only annoyed by the 'supporting' line, he doesn't seem to care that he was called a homosexual.
The relationship between Mori-senpai and Honey-senpai seems rather suspicious.
The twins Karou and Hikaru are as ambiguous as they come. They play up the Twincest angle for all it's worth for the benefit of their fans and to draw customers, but they're often just as close even if they don't have an audience or are completely alone. There's also the probable crush on Haruhi to consider, but that doesn't arise often.
Gilbert Nightray/Raven is practically in the Transparent Closet by the end of the series. He's shown no interest in the many females that fawn over him at parties but constantly fawns himself over Oz, his chosen master and Living Emotional Crutch. He's also quite feminine in appearance; the manga artist likes to have him dress up in girls clothes.
And Vincent, is sometimes implied to have feelings for his brother Gil based on his affectionate Yandere obsession with Gil. And then there's his Long-Haired Pretty Boy appearance and hatred of woman.
Leo often teased Elliot for being so feminine, what with his knowledge about the language of flowers and organic soaps and all. Then, there's how Elliot isn't all that interested in women and one guidebook comic in which he gushes over Cheshire Cat, who is a Cat Boy but just drops the happy when Cat Girl Ada shows up.
Peacemaker Kurogane: Most of the characters are pretty strongly implied to be gay or bisexual. Heisuke makes more than a few references to men and boys he finds attractive or may or may not have slept with. Saitou, while he may or may not actually be interested in men (who knows with him?), is willing enough to pretend to be for information. And general dynamics of Ho Yay between various cast members aside, there are always Hijikata and Okita, who always seem just one step shy of being an Official Couple (with Hijikata's voice actor going so far as to respond to a remark about his character having given up romantic pursuits for his mission with, essentially, "Uh...no"). The shinobi Susumu often cross-dresses (quite convincingly) to gather information, blushes when Tetsunosuke mentions that he and Testsu are friends, and when Tetsunosuke offers him comfort by trying to touch his hand following his sister's death Susumu tightly grabs Tetsunosuke's hand in his. Lastly there's Pretty Boy Suzu, based on his fanboying of Yoshida's sex appeal and his relationship with Tetsu before becoming a Depraved Homosexual in the sequel.
Tucker, though despite the way he dresses, he has a very deep, masculine voice, but still manages to be flamboyant.
Burgh, a fashion designer who wears tight pants and a scarf.
Zoey is usually claimed to be this, for her short hair and habit of dressing almost exclusively in boyish pantsuits for contests, and being very touchy-feely with Dawn.
James is often the subject of discussion as to whether he's Camp Gay (often crossdresses, campy mannerisms and obsession with his looks) or Camp Straight (crossdressers are usually hetero, straight Bishōnen often have campy mannerisms, and he's had several crushes on girls including [very briefly] the psychopathic Jessie-lookalike Jessebelle). The dub dialogue usually exaggerates the former while also adding a few confusing signposts in the other direction; given this is Pokémon, it's unlikely the question will ever get an answer.
Pokemon themselves are no exception to this. Meowth has a Foe Yay driven relationship with Pikachu (it changed to straight Ho Yay at least once), has had homoerotic fantasy spots about Giovanni, and has fallen for James on one occasion (due to mood-altering Shuckle juice). Ash's Oshawott has the same sort of adoration towards Ash as Chikorita, Aipom, and Gliscor had; the former two of them are confirmed to be female and in love with Ash at one point.
Bugsy in Pokémon Golden Boys. He's a young bishonen boy, even more so than in the games. He's constantly blushing and acting sweet around Gold. You may think this is just his personality, but he acts differently around other people.
Homura:(explaining her motivations) It's only natural that you don't understand. Yes...No one in the world could possibly understand. This emotion is mine alone. It is for Madoka alone. (...) It is the pinnacle of all human emotion. More passionate than hope, far deeper than despair. Love.
Kyouko has a lot of signs of having a crush on Sayaka, and her and Mami are shown to have been very close in Farewell Story and Different Story, but again there's nothing official.
Sailor Moon Movie R presents Fiore whose (supposedly) only friend on Earth was Mamoru/Darien a.k.a. Tuxedo Mask. When he returns, he's possessed by the Xenian Flower and becomes a Yandere for Mamoru, wanting to be his Only Friend and kill off Sailor Moon.
Saiyuki: Genjo Sanzo is hinted to be gay as it shown in the first season that he did he not get mad at all when a gay drunk came on to him in a bar:
Guy:(Leers and holds Sanzo's face) You're so pretty that you look like a woman. GS:(Calmly nonplussed) I'm a man though. Guy:(Leers even more) I don't mind. GS:(Remains placid) Fool.
It should be noted that Genjo Sanzo is the grouchy antisocial type who is usually averse, rather violently so, to both physical contact and smalltalk even with his close friends, much less random strangers.
Moe Morita / Flamenco Sapphire from Samurai Flamenco. She frequently blushes around Mari, an older girl in her idol group, and reacts dreamily whenever Mari playfully kisses her. At one point she's shown expecting a kiss from Mari, and not only becomes visibly disappointed when it doesn't happen, but later states that she doesn't mind being manipulated by her.
Mokuzu from Satou Kashi no Dangan wa Uchinukenai. She says she is a mermaid who needs to find a friend within a certain timespan or she will die, directly paralleling The Little Mermaid except for the romantic part. She is drawn to the protagonist, Nagisa, and attempts to be her friend. Mokuzu attracts the attention of a boy in her school but doesn't give him the time of day and is utterly uninterested in him. She only went on a not-date with him because she wanted to spend time with Nagisa. She even ignored him though that was because he was speaking into her deaf ear and she couldn't hear him. Nagisa and Mokuzu end up trying to runaway with each other but... It ends very poorly.
Miki from School-Live! had a very strong friendship with her best friend Kei that is all but romantic. She tends to have a large amount of blushing moments around the other girls as well. This is more obvious in the anime, as it removed the other survivors (and thus Kei's brief male crush) and put emphasis on Kei's and Miki's relationship.
Miku Kohinata from Senki Zesshou Symphogear is this. At first, anyway. Any ambiguity disappeared in G when episode 10 revealed that the reason she could link up with Shenshou Jing is because of her love for Hibiki.
Yuu falls between this and Ambiguously Bi in that while he blushes around girls and acts appreciative of their feelings for him he acts much more interested in Mika. He also shows no reaction when seeing Shinoa and Mitsuba in the shower and in the fanbook Yuu acts disinterested in Mitsuba wearing civilian clothes but when he sees Yoichi wearing them he exclaims "Oh! Those civilian clothes look seriously good on you, Yoichi!" He also responds "shut up" when asked what he likes in the opposite sex.
At one point in the manga, Shinoa jokes that Kimizuki "swings that way" to the rest of the squad who all look visibly shocked. Yoichi reacts with, "He does?!" while blushing.
Shinya shows little interest in women (including his former fiance) and flirts with Guren constantly. His answer to "what he looks for in the opposite sex" in the official fanbook almost seems to imply he's "tired" of trying to be with women. Also, in the drama cd translation the girl crazy Goshi says they need to spend a Christmas with girls before they go to war to which Shinya responds "I'm not sure about the part with girls but I support having a Christmas party."
Kumiko from Sound! Euphonium comes off as this in the anime adaptation. In the books she's at most Ambiguously Bi. The anime removed or toned down almost all of her scenes with her male love interest, Shuichi, while in return it amped up the Homoerotic Subtext between her and Reina to excruciating levels. The Duet Bonding scene between the two, with all its romantic overtones and Reina grazing her finger on Kumiko's face to her lips, is only the tip of the iceberg. Kumiko seems utterly uninterested in Shuichi (and in fact in the books, others had to tell her that she liked him in order for her to notice her own feelings for him) despite his obvious crush on her. The anime ultimately ends on No Romantic Resolution with either Shuichi or Reina however she does give a very heartfelt love confession to Asuka. Whether Kumiko's confession was in a sisterly or romantic context is left vague.
Desslok from Space Battleship Yamato is supposed to be straight, and has slept with at least two women (Starsha and Mela). And yet he has male bath attendants who rub him down vigorously and then clothe him (no, really) and he hits on his generals. And he had an entire canon song written about how he and Wildstar are "bound together" and "unable to live with it anymore". And Zordar, who ignores his girlfriend who is right there and can see everything to hug Desslok. When she got revenge on Desslok and Zordar found out, he said he would have killed her if he wasn't so busy, and did kill her in the original as soon as he got an opportunity. Not to mention Talan, Desslok's faaavorite general, who begs to be sent to prison with Desslok and bursts into tears on the spot when he's told he can't. In Farewell, Sergeant Knox shouts "I LOVE YOU!" to Wildstar (at least in Japanese). Wildstar and Venture do some bizarre wrestling when they're fighting over Nova. Wildstar and Ryusuke also have a fight while the narrator says how Ryusuke felt such new feelings within him. It's like the semi-canon Cast Full Of Gay.
Sugata Shindo; from Star Driver. He does love and care for Wako, but nowhere has it been shown that this is a romantic love. Also, his professed "curiosity" about Takuto as well as his gay subtext-dripping conversations with Head are signs that are too big to ignore...
There's also Shingo Head's currently comatose lover from fifteen years prior, who with the way he looks and talks is only ambigous because the creators didn't directly say anything about his sexuality.
Riho and Chimo of Tamayura start living together quickly after they meet, and they never seem to show any interest in guys (despite both of them being rather attractive, and Chimo even having a persistent male suitor). The series contains some hints about their relationship status, such as their subtle display of intimacy as they watch the New Year's sunrise together.
It's not really dealt with in the anime itself, but the fifth Tiger & Bunny drama CD strongly implies that Pao-Lin has a crush on Karina. The fact that Pao-Lin is a stereotypical Tomboy and usually dresses in male clothing adds further fuel to that particular reading.
Sunny from Toriko is extremely flamboyant, obsessed with beauty, wears pink, and licks other men with his hair. He is also trying to steal Komatsu away from Toriko (because he's beautiful when he cooks).
Going into huge (Visual Novel only) spoiler territory with Umineko, but what's up with Jessica and Kanon? Did she seriously not notice she was in love with her best friend, who is usually female? For that matter, since Yasu's gender is so ambiguous, it's hard to tell which relationships in the series are straight and which are gay.
Lucia from Venus Versus Virus. Nothing is said about her bond with Sumire, and it doesn't go anywhere on-screen, but it's heavily implied she harbors feelings for her.
Anna from When Marnie Was There develops a very close and intimate friendship with the titular Marnie that consists of having a Old-Fashioned Rowboat Date, cute dancing together, and declaring their love for each other. She also gets quite upset when Marnie shows interest in a boy. However the last minute reveal that Marnie is Anna's Dead All Alonggrandmother as a child really muddles up the story's intentions.
In Yu-Gi-Oh! GX, Doctor Chronos/ Dr. Crowler dresses very flamboyantly, although there was one episode where he - like all the other males - seemed attracted to Dark Magician Girl. Also, there was Johan/Jesse Anderson, Judai's new best friend who wears frilly shirts, uses the ace card Rainbow Dragon, and spends a little too much time with Judai for us to believe he's completely straight. His subtext with Judai is spread so thick that it's noted on in-universe.