Let us begin with the fact that Ichigo and Uryuu's mutual initial reaction to each other is to stalk one another at school and around town (Uryuu when Ichigo first becomes a Shinigami, Ichigo once Uryuu reveals his powers), instead of, y'know, having a conversation, or even punching each other in the face, like Ichigo usually does to get to know people better.
Not four minutes into episode twelve (in the English dub) Ichigo tackles Ishida to the ground, panting rapidly. Ishida responds "why is your face so tense?" Sure, Ichigo is pissed about the hollow, but if you ignore that..
In episode 14 as Ishida is saving Ichigo's life (by standing on Ichigo's sword and letting his bow get huge) he tells him the following: "If we both don't survive this we won't have each other to beat up!" Hell, pretty much all of episode 14 was definitely symbolic of... something. Uryuu's past is shown to be analogous to Ichigo's (horrible death of beloved parent figure results in burning need to prove worth) but without being shaped by positive relationships like Ichigo's with his sisters and with Rukia. Ichigo's reaction to Uryuu breaking down in tears is, "Shit, I can't hit a guy who looks that pathetic..."
Chapter 214: Even as Uryuu is becoming increasingly convinced Ryuuken's trying to kill him instead of restore his powers, he's still aware of the battle going on between the Shinigami and the Arrancar, and worried about Ichigo.
Chapter 241: The loophole Uryuu exploits in his promise to Ryuuken applies ONLY to Ichigo, as Ichigo is the only current Substitute Shinigami. He seems to have been willing to promise away contact with any other Shinigami...as long as it wasn't Ichigo.
Ishida's desperate attempt to stop hollowmode!Ichigo from tearing up what he believes is Ulquiorra's corpse. Not for any concern about Ulquiorra, but because he knows how horrified Ichigo will be when he comes back to himself. Then he gets impaled on Ichigo's sword. And forgives Ichigo for stabbing him immediately.
Ever since the time skip, this seems to be taken even further.
Chapter 426: Not only is Ishida reintroduced kicking ass in perfect synch with Ichigo, but they proceed to argue because Ichigo is the one more concerned about maintaining Ishida's honor student reputation.
Chapter 429: Orihime ends up being the one who tries to get Ichigo to cop to what's bothering him...but only because she got there a little faster than Uryuu, who came over with the same intention.
Chapter 430: Uryuu is struck down by a mysterious attacker but refuses to tell Ichigo what happens, and snaps at Ryuuken when he points out that sharing information is in everyone's best interest. Maybe Uryuu was just generally irritated by his father's presence, but this exchange suggests that his biggest concern was keeping (depowered) Ichigo out of danger by preventing him from running after the attacker. Ichigo's reaction? To run straight to the creepy dude he's been avoiding for several chapters because Uryuu getting hurt means he needs his powers back NOW. note The anime drags Ichigo's unwillingness out another 24 hours, taking the focus off Uryuu.
Chapter 491: Ichigo's reaction to Qilge's...unique...appearance in Vollstandig is "If Ishida ever transformed into such a sad excuse for a costume, I'd have to cut him down on principle!" Oh really, Ichigo. Got a lot of opinions about Ishida's wardrobe, now?
Chapter 530: Masaki and Ryuuken are first cousins, which makes their sons second cousins. Awkward! By American standards, at least. The Quincies clearly have no problem with it at all, since Ryuuken and Masaki had an arranged engagement as teenagers.
Chapter 544: Uryuu has been established as Yhwach's Unexpected Successor, and now appears beside Yhwach with Haschwalth as Co-Dragons. This sets him up as a possible Boss Battle for Ichigo, if only to finally reveal his hidden motives. And given that Ichigo is known for insight into his opponents' psyches...
In episode 333 after seeing Ichigo get hit by an attack and falling out of the sky Renji runs after him to save him while screaming Ichigo's name. And in episode 334 when Ichigo wakes up Renji is shown sitting by his side watching over him and whispers Ichigo's name.
Ichigo and Renji also tend to butt heads within moments of trying to do almost anything, often to the point of immediate physical violence, but will nonetheless put their lives on the line for each other at a moment's notice.
Chapter 473: Byakuya defeats Tsukishima not just because it's the right thing to do, but because Tsukishima has Mind Raped Ichigo and basically ruined his life. The kicker? Byakuya has, in fact, been brainwashed into thinking that Tsukishima was his mentor in swordsmanship. Ichigo is STILL more important to him. Not even Chad and Orihime were able to overcome the brainwashing and help like that.
Kenpachi/Ichigo: Ken-chan seems to get off on fighting, so many of his scenes with... anyone... can carry some suggestive tones. And Ichi is his best friend.
Grimmjow/Ichigo: Dunno how Ichigo feels about it, but Grimmjow, initially thinking him as an annoyance that scarred his chest, gradually grew more and more obsessed with defeating Ichigo. Some time after their second fight, Grimmjows' attitude towards Ichigo seemed more intense, and is now determined to beat him. The fact that Grimmjow is Ichigos' Evil Counterpart just adds more fuel to the already-sizzling fire.
He chose to keep that huge scar on his chest just so he could be reminded every day of how Ichigo defeated him.
The English dub doesn't help matters any. What with Grimmjow demanding Ichigo say "That you want to get a hold of me and rip me apart!"
Or saying how much he's been waiting to fight Ichigo at his full strength and excitedly asking if Ichigo feels the same way. When Ichigo says he doesn't, Grimmjow gets pissed and screams "don't give me that pathetic lie!"
After their fight Ichigo lowered Grimmjow to the ground very gently. At least, he did in the anime.
Ulquiorra/Ichigo: Ulquiorra puts his arm through Ichigo's bare chest which results in a gaping hole. Grimmjow later mentions that Ulquiorra only puts that hole on his favorite victims. And later on Ulquiorra blasts Ichigo again which causes the hole to get even bigger. Oh, and how he gets noticeably pissed when he finds out Grimmjow made Orihime revive Ichigo after he defeated him for the purposes of fighting him.
Grimmjow got inordinately pissed when he found out Ulquiorra's been going after "his prey" (Ichigo).
Aizen/Ichigo has catapulted every chapter since then, culminating with the ultimate stalking phrase: "I've known about you since the day you were born." Thank you, Aizen. Your constant smirking, lack of personal space and smexy hairdo have put you on the level of Foe Yay as the Borg Queen and the Joker. Although, considering that these continued revelations probably mean that Aizen sent Grand Fisher to kill Ichigo's mother. Meaning this could be Aizen/Isshin, with Ichigo being the kid Aizen wants to buddy with. Not to mention Aizen telling Ichigo "You are the very thing I'd been searching for" and telling him not to disappoint him because he knows he's a strong fighter.
Aizen leaves Ichigo to destroy his hometown with a promise to come back later to eat him. Aizen-sama only knows what the hell that means.
Even before that after Aizen reveals himself as a Big Bad he informs Ichigo "For a human, you were truly fascinating."
On a slightly lesser note, Muramasa got this with Ichigo during their last fight, ending with Ichigo holding Muramasa's hand as he slowly dies, happy to have found someone that genuinely connected with him, that "connected" part is up for interpretation, of course.
Not only in the last fight but mainly with all their fights, Muramasa insisted that he was greatly intrigued by Ichigo, that he had an interest in him.
And Tobiume once states to Haineko "You know, Muramasa-san seemed pretty infatuated with him (Ichigo), didn't he?"
Mayuri/Ichigo: Their interactions are... interesting, to say the least. Ichigo appears to have merrily escaped Mayuri's wrath for now. But it looks like Mayuri now seems veryinterested in him - both because of Ichigo's happy comment which pissed him off, and because of Ichigo's potential.
Toshiro and Ichigo have a bit of this as well. Specifically how Ichigo always calls him Toshiro without the usual "it's Captain Hitsugaya" rebuke.
And the Ho yay level between those two increase very much in the second movie; Diamond Dust Rebellion.
Chapter 427. Ginjou: (to Ichigo) "You like chocolate? That's cute."
Kokuto gets some with Ichigo, and by some, we mean they have a Held Gaze moment...
Then there was this one (anime-only) fight with this snake-themed badguy.
Ichigo: I WILL NOT LET YOUR SNAKE TAKE MY BODY!
Ryo Utagawa: You're full of openings.
From that same episode Kariya the leader of the Bouts offers We Can Rule Together and "wants to get into his body."
There has been vibes of Ginjou/Ichigo lately.
Not to mention Ginjou Taking the Bullet for Ichigo when Tsukishima attempted to cut Ichigo, as well as Ichigo's reaction and Say My Name moment.
Which went right into Foe Yay in the following chapter.
And in chapter 477 when Ichigo defeats Ginjou they are shown to stare into each other's eyes with Ichigo giving Ginjou a sympathetic look and Ginjou thinking "Ichigo..." Ginjou also shows signs of humanity as a result of his fight with Ichigo and Ginjou worries about whether or not Ichigo would become like him.
And in chapter 479 Ichigo states that he wants to take Ginjou's corpse back with him to the normal world to give him a proper burial.
Even Tsukishima and Ichigo have some. Like in chapter 456 here.
How can there possibly be no mention of Ichigo/Inner!Ichigo? Foe Yay levels between them is through the roof! Though that's subverted now that it's revealed Shirosaki is the true Zangetsu who really only wanted to protect Ichigo at all costs.
Chad/Ichigo. Keigo, the lovable idiot, comments in one scene: "What the heck? The two of you didn't go somewhere together, did you?" Chad and Ichigo share a confused look prompting Keigo to scream "Why're you looking at each other?! Don't tell me something happened between the two of you over summer vacation..."
Also, Chad has sworn to only fight if its in defense of Ichigo. About as romantic a sentiment as you can get.
In chapter 456 Chad tells Ichigo with a pained expression on his face "I didn't get stronger to hurt you!"
In chapter 485 Chad said he wanted to help Ichigo against their newest enemy even when no one else would.
Keigo/Ichigo: Keigo glomps Ichigo in episode 15 by way of wrapping his legs around Ichigo's torso and his arms around Ichigo's neck.
Mizuiro/Ichigo: according to Keigo Ichigo is the first person Mizuiro has truly gotten close to, and Ichigo's unexplained disappearances caused him to retreat further into himself refusing to answer his cell phone and going to school alone.
When they meet in Soul Society Arc, Soifon furiously fights her old master and mocks her for being a exile. But by the end of their battle, Soifon breaks down crying. "Yoruichi-sama, why didn't you take me with you?"
Soifon stalks Yoruichi in an attempt to see her naked, and in the video games expresses jealousy that Ichigo and Yoruichi had a bath together.
Certain flashbacks provide some very sweet scenes featuring young Soifon looking flustered when young Yoruichi asks her to treat her with less formality, or Yoruichi resting her head on Soifon's lap to stare at the moon. With red petals in the background. Yea.
Yoruichi demonstrates the proper kendo form to Soi Fon... by doing the standing equivalent of spooning.
Soifon has also received a Bridal Carry from Yoruichi a few times, such as here◊.
This is also speculated by some to be the reason Soifon refuses to help the Vizards until Hachi says he'll seal up Yoruichi's best buddy/possible love interest Urahara for a month.
The ending themes seem to back this up. Human Yoruichi made her first appearance in Soifon's captain ending theme and then there's the fact that in the 7th ending theme they are essentially cuddling.
Let's just go ahead and say this one is practically canon, at least on Soi Fon's part. It's a running gag in the manga omake's that whenever the Shinigami Woman's society tries to do or make something, she votes for it to be Yoruichi-themed.
Also, there's this moment in the anime where Soi Fon blushes and fangirls over pictures of Yoruichi.
This scene where Soi Fon blushes and acts flustered when she remembers how Yoruichi had her in a Bridal Carry.
And then there's this scene where Soi Fon blushes when giving chocolates to Yoruichi.
When Soifon first laid eyes upon Yoruichi when she was young, she likened it to looking upon a goddess. Soifon admired Yoruichi's strength, beauty, and nobility to the point where it passed admiration and became worship.
In chapter 479 it seems Soifon's obsession with Yoruichi is still strong, hinted when she tells Ichigo "Don't get so familiar with me. You're worthless to me if Yoruichi-sama is not with you!"
One-sided perhaps, but Yumi hiding the form of his shikai so he could stay in the 11th divison with Ikkaku? That's a bit much even for good friends. One episode revealed that the two have been traveling companions for a very long time, even before becoming Shinigami...
He's not only willing to hide his shikai, he's willing to die rather than reveal it and risk anyone seeing. Once again, just a little hardcore for being friends.
Ikkaku can recognize Yumichika's laugh and be distracted by it while both are fighting in different fights... and there was at least the distance of a town between them.
In a similarvein, there's their own zanpakuto, Hozukimaru (Ikkaku) and Ruri'ro Kujaku (Yumichika), who spent more time together than with anyone else, besides their masters.
And let's not forget how Yumichika went absolutely nuts when he thought Ikkaku had been killed, threatened Hisagi when he wouldn't let him run to Ikkaku's aid, and eventually had to be knocked out by Kira.
And this is AFTER what Yumichika said to Keigo about not helping Ikkaku and calmly making funeral arrangements. Seems Yumi's only fine when he KNOWS Ikkaku's okay ("I knew you were alive, Ikkaku!").
There's one very Ho yay-ish moment in episode 229 of the anime wherein Ikkaku and Yumi are sitting in a park, with Ikkaku bitching about having to stay with Keigo and his sister. Yumi smiles, says they should be grateful for the hospitality, before reaching over and unbuttoning Ikkaku's jacket. Admittedly, he most likely did it because Ikkaku was wearing a silly t-shirt underneath and he was going to make fun of him, but still.
We also see, through the power of flashbacks, even though the two were best friends before becoming Shinigami, Yumi was more like Ikkaku's wife, following him around (in a floral kimono, no less) and looking after him after fights.
How 'bout any of the same-gender shinigami/zanpakuto relationships? Weird case of Selfcest, true enough, but they're beings unto themselves - people in their own right - just spawned from, and based on somebody elses' consciousness.
Rangiku and Haineko. Since Haineko is portrayed more in the light of a teenager, despite looking in between 21-28, it's easy to view their relationship as that of a mother/daughter type, more specifically in episode 262. They have similar interests in fashion (Rangiku likes looking "cute", Haineko likes looking "sexy", both have good taste in their clothes), love drinking sake, and enjoy teasing others, male and female alike. Plus, don't forget the moments that have them very close together, with arms wrapping around each others' shoulders and faces close enough to make it seem like they're about to kiss, sometimes while flirting. For the latter, there was a moment where they were in the real world, wearing school girl outfits, Rangiku creeps up behind her, slowly moving her own face to Haineko's, whispering "All that's keft..." in her ear, before moving Hainekos' shirt down to reveal more of her cleavage, saying "You look much hotter this way". Finally, in episode 265, we have Haineko lying unconscious on the ground, Rangiku tickles her cheek, gently saying (like how a mother would) that if Haineko won't wake up, she'll "ruin her pretty face".
And before that, during their fight, Haineko slashes at Rangiku's chest, ripping off enough fabric to cause her boobs to jiggle. Cut to a smirking Haineko coyly licking the corner of her lips, saying "I was trying to make you sexier".
In Episode 232, Rukia fights the manifestation of Sode no Shirayuki, her zanpakuto; there are several lines on Rukia's part musing about how beautiful she is, and the battle ends with Rukia and Shirayuki pressed face-to-face in a Six-Rod Light Prison. And let's not forget Shirayuki reaching almost tearfully for Rukia's hand before Muramasa intervenes.
Tobiume/Momo. What with Tobiume praising her as a MarySue after their fight, which was before Muramasas' influence on her was lifted.
Byakuya/Senbonzakura and Hitsugaya/Hyorinmaru for that whole "loyalty and obedience" bit, Yumichika/Kujaku and Ikkaku/Hozukimaru for being almost exactly alike, Hisagi/Kazeshini and Soifon/Suzumebachi for being total opposites, need I go on?
Hitsugaya expresses his appreciation for Hyorinmaru, and is caught in his arms when exhausted!
Can't forget this scene. Yes, that's Muramasa talking.
There's also Nanao/Kyokotsu - the ninja girl half, that is. Thanks to Nanao, we've learned that, other than being a borderline sociopath, Kyokotsu is actually quite shy around people and has a very hard time expressing herself, leading her into becoming coldly distant and secretive most of the time. Case in point, Nanao is the Cool Big Sis, with Kyokotsu as the cute and shy little sister.
Haineko/Tobiume. Even as they argue almost every time they share a scene, they're nearly always seen hanging together, and later, while the teasing and arguing remain, it's more on the playful side, something both seem to enjoy pretty well.
Haineko/Yoruichi - Aside from playful taunting and Yoruichi posing for them (her way of showing that she's sexier), once her way of escaping was blocked, Yoruichi muses on how she'll have to fight more seriously (i.e. hurt them, not knock out or bind), earning a flirtatious smirk from Haineko, coupling it with a mischievous "Hmmmm", as if she was gonna say "I like the way that sounds". Plus, after forcing Yoruichi back underground, Haineko says a very playful "Hiiiii", once again flashing that coy, yet cocky smirk. Note that this was when Haineko was under Muramasa's influence, so chances are that they're on presumably friendlier terms nowadays, which means more "fun time with fellow felines!"
Ichigo/Tensa Zangetsu. Anyone remember that stabby bit in chapter 420, and the crying? And afterwards... "What you want to protect is not what I want to protect. What I wanted to protect… was you, Ichigo." Apart from being a Tear Jerker, it could easily be implying something else...
Tesla towards Nnoitra. "Nnoitra-sama!" indeed. For one thing, it's implied that Tesla wears an eyepatch over his right eye, to show his admiration and respect for Nnoitra, who also wears an eyepatch. To a certain extent, Tesla seems to idolize Nnoitra. For example, he shielded him against Chad's last assault, despite receiving criticism from Nnoitra himself for doing so. Tesla has also shown concern for Nnoitra's well-being, running to his side when he is hit by Nelliel's Cero Doble and crying at his death.
The dub made it even more explicit, with the way he call's Nnoitra "Master" and all.
Renji to Byakuya: "If you had died, who would I aim for to get stronger?"
What about that scene right after, which went something like this:
Renji (to Byakuya): "Captain... I..."
Ichigo: "RENJI!" (Comes barrelling in, looking for Rukia and ruining the tension.)
Renji: "Shut up! What do you want? I was just about to say something heartfelt!"
Isane's strong admiration for Retsu Unohana.
Explain why Aizen and Gin aren't listed here. My God, there's not much in canon besides the "I have never considered anyone my Lieutenant but Gin" scene, but when you get into the theories on subtext and then the fanfics... Again, My God.
So much between Izuru Kira and Gin Ichimaru. Or at least on Izuru's side.
Some of which is arguably present in Rock Musical Bleach.
And if we go to the manga... the words that Rose used to describe the either dead or on the brink of death Kira in chapter 495 simply ooze with Ho Yay.
How about Orihime and Rukia? If this doesn't scream Les Yay, then the chapter it goes with does.
Yeah, if Hiyori hadn't interrupted it certainly seemed like that conversation was going in that direction. Rukia and Orihime are an interesting case though, Orihime has stated repeatedly that she loves Ichigo (though not to him in so many words) and does eventually sees Rukia as a threat but her reaction isn't typical, and semi-justifiable anger, but something more like rejection (depending on how you read it) suggesting a latent and probably subconscious attraction. As for Rukia, apparently she didn't have much of a social life as a soul reaper prior to the events of the manga (it's even implied Orihime is the first new friend she's made) and as a child she was a tomboy who hung out with a group of boys, so interpret that how you like.
Plus, Orihime tends to refer to Rukia with much admiration:
Orihime: "Kuchiki-san is really something, isn't she? Even though Kurosaki-kun was really, really upset, she was able to cheer him up with just one whack...She's so kind and strong and pretty. I really like her!"
In the Bount Filler arc, Orihime frees Rukia from the influence of a Bount by hugging her and using her powers on her.
I spot a double Les Yay, look at where Chizuru's arm is, and her expression. Tatsuki's expression doesn't seem to match her accepting gesture, though.
The 10th opening, titled "Shoujo S", has some scenes where Rukia and Orihime dance together and hold hands.
Hush, everyone! Father and Mother are talking!
They're old student colleagues, now fellow captains who've been best buddies for more than three thousand years. With that amount of time they spent trust each other so completely that they'll even break the law together without asking any questions of each other, and understand how the other thinks even though they're total opposites. Fatherly and kind, their role in the story is usually mentoring the younger characters (who actually get to fight /mini-rant), expositioning, and embarrassing people (Byakuya, Nanao, and Hitsugaya are favorites).
And then we get the battle with Starrk. Protagonists trying to kill people in shounen are not supposed to be so casual about it (or in Shunsui's case, fight so dirty). They even point out everyone else is getting 'serious' in a Final Battle manner. Quietly confident, dealing with one another and fighting Starrk with ease, you can easily believe they've been doing this kind of thing for centuries, confounding enemies (Starrk doesn't know what to do with Ukitake, and they know it). And then there's Kyoraku's reaction to Wonderweiss. Put it down to shock, fine, but in that fight it was the only moment he got upset. They work too well together for there not to be subtext. As this troper had the supposedly Real Life Spartan example of Battle Couple explained to her once - 'the idea was that if you killed one person, the one behind him now had a really good reason to kill you. And had a sword.'
Kyouraku (who Ukitake has effectively got wrapped around his little finger) calls him "iro otoko" which means "lover, lady-killer, sexy guy" (make of that what you will).
Shunsui Kyoraku is the Brilliant, but LazyChivalrous Pervert who would rather spend his days sleeping, drinking, or flirting. But when Ukitake was stabbed through the chest by Wonderweiss, it was the one time he lost his cool, as he instantly responded by trying to attack the arrancar.
This happened to Ikkaku, too, in the filler. Tessai had him half-stripped and Ururu was helping to hold Ikkaku down. It made Yumichika very upset.
Musn't forget Kisuke/Mayuri! There's so much Foe Yay there it's crazy. That jail scene was pretty heated and you can bet that Mayuri reacts super pissed off at Ichigo upon mentioning Urahara's name. Methinks Mayuri and Urahara might have a similar situation to Soi Fon and Yoruichi. Abandonment issues much?
For Orihime's worst enemy in the Hueco Mundo arc, Loly has a lot of extremely uncomfortable Foe Yay / Les Yay with Orihime. Both times she and her sister go after Orihime, it's very easy to read their interaction as that of a Psycho Lesbian rapist and her intended victim or a Depraved Bisexual targeting the girl she's jealous of. To elaborate, whenever she's not trying to kill Orihime, Loly is stroking her hair, invading her personal space, pinning her against walls, calling her "Orihime-chan", almost seductively whispering in her ear, caressing her face, tearing her clothes... you get the picture.
"I can do whatever I want to you...and he won't get mad at me."
Yammy and Ulquiorra? Watching their interactions, it is really hard to see a reason why Yammy keeps tagging along with Ulquiorra and always wanting to help him in spite of Ulquiorra's general jerkiness. Logistically speaking, its probably for the best that Yammy seems so Uke about it.
Grimmjow/Ulquiorra. Especially on Grimmjow's part, what with knowing things about Ulquiorra that Ulquiorra hadn’t even known about himself. And the shirt grabbing. And the very phallic-looking cover page on the Corrosion of Conformity chapter.
There's also Wonderweiss and Tousen in the one anime omake where Wonderweiss is rubbing up against Tousen and then the background turns pink with sparkles and flowers.
Chizuru is a very open and proud lesbian and generally makes advances towards any girl she considers attractive. She has a very open infatuation with Orihime. This includes calling her "Hime" (meaning princess) and "my Honey!", trying to hug her and gaze at/fondle her chest every chance she gets, and complimenting her. Unfortunately for the shonen audience, her advances are invariably thwarted by the protective Tatsuki, who Chizuru has commented she would also find quite attractive if not for her boyish persona; though if anyone else interferes or says anything negative about Orihime, Chizuru usually flies into a homicidal rage. Regardless of her primary crush, Chizuru has also ogled other female members of her circle of friends on occasion, namely Mahana, Michiru, and Kunieda, as well as Rukia.
She once glomped Rukia from behind and was literally drooling over her at the start of the Bount arc, openly gazing at her chest while saying "Kuchiki-san's are peaceful and so very adorable". The closest Chizuru's ever gotten with Orihime is grabbing her... considerable assets. This was changed in the anime to hugging Orihime around the lower chest, with her forearms pushing Orihime's breasts up.
Let's not forget her superhero persona, named "erotic", only has powers that work against girls, and killed an Arrancar (girl) with "Hyper Erotic Mode".
She also once had a throwaway line in the manga where she declares that Orihime's cuteness is "Giving her an erection." Whereupon she's promptly pervert-stomped by Tatsuki. A doujinshi of Chizuru having a relevant daydream in class soon began circulating the internet.
Amagai/Ukitake. This clip featuring a drunk Amagai glomping a surprised Ukitake.
Tatsuki/Orihime. There's Tatsuki's constant protectiveness of her, especially from Chizuru, and Orihime's promise to protect Tatsuki later on, but for this troper, it was the fireworks scene that did it.
Not to mention how in the past Orihime used to be tormented by other girls trying to cut her long red hair. After Tatsuki saved her, Orihime vowed never to cut her hair again as a symbol of their friendship.
Watching season one on Hulu, I'm struck by how much confusion Tatsuki and Orihime's relationship causes. Every third review seems to be speculation on whether or not they're in love.
Not to mention Orihime likes to call her "Tatsuki-chan". It's always "-chan" or "-kun".
And then there's how Orihime destroys the Numb Chandelier, after first declaring "I will never forgive those who hurt Tatsuki!"
Orihime's hollowfied brother Sora also tries to kill Tatsuki (and Ichigo) for taking his place in Orihime's heart.
Hisagi/Kira. They're usually together most of the time they're in omake segments, and even spent some of the time standing next to each other as they barely have any clothes on.
Hisagi/Renji. Seem to be on pretty good terms, mostly on omake segments, plus their looks and physique are very popular with fangirls, so it's natural for them to be paired together.
Hisagi also gets this with Komamura and some Foe Yay with Tousen and Findor.
Kira/Renji. There was a scene in the anime where both got drunk and Kira got really close to Renji's face.
Luppi and Gin Ichimaru seem to have been on good terms, as Gin comments about being lonely after Luppi's death, citing the fact that the two often spoke.
Yoshi and Rukia in the Bount filler arc. Also overlaps with Foe Yay. Yoshi calls Rukia "cute", seductively says that she's making her excited, gets close to her, and tears her clothes with her sword.
Rock Musical Bleach - Live Bankai Show also features Rukia laughing creepily when she and Momo Hinamori outnumber Yoruichi. She starts shouting loudly that breast size is unimportant. Cue Yoruichi singing and placing each of their hands to her breasts multiple times throughout the song.
Based on their scene in chapter 241, Kurosaki Isshin and Ishida Ryuuken seem to have the same kind of comfortably vitriolic relationship as their sons. And then you look more closely at what they're doing and saying: Isshin is pleasantly surprised by how familiarly Ryuuken addresses him and remarks on how hot his new Shinigami robes look; Ryuuken shoots him down while lounging against a ledge, jacket off and tie loosened, smoking languidly. All that panel needs to be the page image for Smoking Hot Sex is a little nudity and a bed with rumpled sheets.
Tatsuki remarking about how beautiful Rangiku was in chapter 412, and thinking "Damn that Ichigo, I never heard anything about him knowing a babe like that."
Komamura and Tousen have a surprisingly tender moment that could possibly be seen in this manner, right before Tousen gets blown up seemingly by Aizen
Szayel Aporro Granz, the 8th Espada, toward Ishida Uryuu. (Arguably, Renji too — all three of them have some interesting lines in those chapters, whether Szayel telling Renji "he's not into that sort of thing", Renji telling Ishida "flattery will get you nowhere", and Szayel's extreme reaction to learning that Ishida is a Quincy).
Chapter 448: Riruka's rather.... interested◊ in Orihime.
In 478, Riruka wakes up and finds Orihime in her bed.
In 479 Riruka goes into the dere part of her Tsundere persona and thinks "Thank you, Orihime, for crying for me."
And Orihime likes to act very friendly towards Riruka and call her "Riruka-chan". Yeah, at this point, it's safe to assume this Les Yay is deliberate.
There's also some Riruka and Rukia Foe Yay, though not quite as blatant as with Riruka and Orihime.
Momo and Rangiku.
Ishida and Renji. For example, although they fight a lot they're quite quick to jump to one another's aid if one gets in trouble and Renji acted quite upset when he saw Ishida get attacked/tortured by Szayel.
Chad and Keigo in episode 342, where it was revealed that they were at the ice skating rink together before, just before Keigo talked about how it was a popular date spot. Sure, it could be that Keigo just wanted to pick up some chicks with Chad, but after saying that, Keigo and Chad look at each other smiling... and Mizuiro smiles at them knowingly...
Shishigawara is utterly devoted to Tsukishima and is willing to throw away his life for him. And in chapter 478 he carries an injured Tsukishima and says he's glad Tsukishima didn't die. Tsukishima is shown to be touched by Shishigawara's loyalty and tells him "Thank you...I was never alone."
Karin once says in episode 115/116 that "Tatsuki-chan's become a bit sexy since she entered high school, you know." as if it were the most natural thing in the world.
Tsukishima x Ginjou anyone? It has been often said by fans that they argue Like an Old Married Couple, especially since chapter 458. Needless to say, after the revelation in that chapter fanarts of them have begun popping up.
And in chapter 477 we get this scene between a younger Tsukishima and Ginjou. That chapter was just full of not so subtle subtext, with Tsukishima coming back from the dead and screaming Ginjou's namein anguish when he sees him lying there, presumably dead, and going into an Unstoppable Ragerevenge mode which strangely resembles the infamous scene where Yumichika freaked out seeing a beaten down Ikkaku.
In chapter 478 we see Tsukishima acting deeply upset over Ginjou's death and having a Freak Out moment.
Episode 228 beach episode. Rangiku is suspicious when Lieutenant Nanao Ise suddenly has larger breasts than she remembers. She hugs Nanao from behind and gropes her breasts to discover that she's using falsies under her bikini to make her breasts look bigger.
Lisa Yadomaru is often seen reading what seems to be porn magazines with lots of bikini-clad women on them.