Chachamaru's pactio. The way Negi tells her to believe (in him who believes in her) and then practically shouts at whoever oversees the pactios "Who the hell do you think I am?!", followed by Chachamaru looking at the card like her newborn daughter.
Binchou-tan is capable of awakening warm fuzzy feelings on anyone, through its unspeakably cute characters and Ghibli Hills.
Azumanga Daioh, even though Sakaki keeps on being bitten by cats. It's a bit weird when you know what would happen if someone actually got bitten by a cat, though.
It only makes the moments with Maya all the sweeter.
The part where Kaorin does the folk dance with Sakaki. It's the perfect mix between funny and adorable.
The entire Chiyo-chan in a penguin sequence. Sure she is abused a little bit, but she is so incredibly adorable.
Chiyo-chan in general. Take the scene where Sakaki first meets Tadakichi-san: she comments that Chiyo could ride on his back, as she's just about the right size to do so. Turns out, she's already done so, and it's adorable.
Any scene with Osaka in it. Yes, even the creepier ones. If you think she isn't adorable, you're either lying or you haven't seen enough of her personality yet.
Cardcaptor Sakura. Both the manga and anime have the potential to make anyone feel so gooey inside. Even the commanding imperiousness of Yue the Judge, the silver moon spirit that took almost sadistic satisfaction in making things horrible for Sakura and Syaoran, is lost in the face of him being just so sugary sparkly pretty.◊ (And yes he does turn out to be a nice guy).
The main character's catch phrase is "Everything will be all right", which is considered by pretty much all characters where her true magic comes from.
CLAMP purposely made the manga a Sugar Bowl, a story where no one will be judged by who or in which form they love, all in hope that children who grow up watching it can absorb the message. You have one openly gay romance in the show, between Sakura's brother Touya and his best friend Yukito, being portrayed in a healthy and loving light much like Sakura's own.
Hayate the Combat Butler. For such an insane widget series, it has a lot of drama, heartwarming moments and almost all the characters, even the most flawed ones are likable (well, except Hayate's parents) and everyone has so much chemistry between each other. Any scene between Hinagiku and Hayate is bound to leave anyone feeling good and willing to do the same acts of love towards their loved ones that Hayate and Hinagiku do for each other.
Binbou Shimai Monogatari, Kyou and Asu's relationship is just so sweet and heartwarming. Especially, in the (much longer) manga which, among other things, includes a happy version of "The Little Match Girl" with them as the title character. Kinko and Ginko's relationship is almost as sweet. Also, deep down everyone is is a nice person. Yes, even their father.
When Ouran High School Host Club isn't making you laugh from the sheer ridiculousness of its melodramatic comedy, it's warming your icy heart by devoting episodes to reuniting couples torn apart by circumstance or showing just how much the other hosts actually care about Haruhi at the end of the day.
K-On!: On the surface it's supposed to be about a small, four-girl (later five) high school music club...until you get to the cake. After that it's just a wild ride of Beach Episodes, Yui being The Ditz, and other activities...with maybe a bit of music for good measure.
Studio Ghibli: Any of the Studio Ghibli films aimed at children are this. (disclaimer)Make sure to look up a premise to what you're watching beforehand. TV Tropes is not responsible if you're half way into Studio Ghibli's Grave of the Fireflies before you realize it's a Tear Jerker about orphaned Japanese children in World War 2. Just make sure you stay away from NightmareFuel.Hayao Miyazaki unless you want them potentially Ruined Forever.
My Neighbor Totoro, a Slice of Life movie about a loving family consisting of two young sisters, an attentive father, and a mother who is sick in the hospital (but getting better). And the furry, friendly supernatural critters the girls befriend.
Kiki's Delivery Service. An adorable young witch in a wonderful coming-of-age story, three loving mother characters, a surprising and beautiful change of pace when Kiki spends the night with Ursula, Scenery Porn worthy of the Louvre, and a heroic rescue at the end. And a cat romance. The whole movie is like the cup of hot coffee/chocolate Osono gives Kiki when they meet.
Whisper of the Heart. A sweet slice-of-life romance between two young people. The "Country Roads" scene in the violin shop is enough to make even a hardened macho dude sniff.
Ditto its quasi-sequel The Cat Returns - yes, there are some tense moments, but all in all the fantastical nature of the story, the beautiful visuals, and the wonderful Ear Worm ending song combine to make you just feel *happy* after watching it.
Shinryaku! Ika Musume has the title Ika Musume (squid-girl) planing to invade the world, because humans pollute the ocean. Though she might not have been successful with that, the show has invaded your heart. And also causes Awesomeness Withdrawal because it's that awesome.
Despite the characters living in something of a nasty, dangerous world, what makes One Piece good is that it's still full of Sweet Dreams Fuel of all kinds. It's loaded with hilarious and positively warm and fuzzy scenes. And you always come out of reading it feeling NO ONE is alone, and that your true friends will care about, protect, and stay by your side no matter what, and that miracles happen and nothing is really impossible.
You will have trouble finding something more awesome and uplifting than Luffy beating the ever-loving snot out of Arlong and ending the battle by breaking his base in half with one kick. * sniff* So awesome...
The Water 7/ Enie's Lobby arc. Even though it has a lot of depressing parts, it also has the appearance of Sogeking, Luffy going 'LEEE-ROOOOOOOOOOOOOY JENKINS!' on Enie's Lobby and declaring war on the World Government to prove he won't abandon one of his crew. This one cheered. One Piece is very good at taking all the depressing moments and turning them into Moments of Awesome.
At one point in the story the straw hats travel to a world in the sky where nearly everything is made of clouds. Those cloud beds are probably literal sweet dream fuel.
Chopper is so adorable that he could be an embodiment of this trope outside of battle.
Macross7, a lot of it, but especially the scene in Episode 37 when it's revealed that "the Sign of Peace" that a door locked with a riddle requires in the Protoculture ruins is a half-breed, someone born of two parents from two different races. That's when you realize in full force that humanity was nearly annhiliated by the Zentradi, a race of giants that knew only war and destruction, just a few years ago, and they were literally LOVED INTO SUBMISSION... and that it's all happening again, with what what was thought to be a soul-devouring Eldritch Abomination about to be saved by The Power of Rock. All to the notes of the incredibly aptly-named Power to the Dream.
Sket Dance. The friendships. The endless and unique humor. The adorable characters. The endlessly cute and heartwarming relationship between Bossun and Himeko. This manga WILL make your day better.
Haibane Renmei. There's something about Rakka waking up and seeing everyone else just smiling at her.
Strawberry Marshmallow. The two sisters, the weird neighbor, the innocent girl and the British girl who can't speak English. There's a laugh in almost every scene with this group.
Fruits Basket is a great thing to watch marathon-style while in the depths of depression. It's basically a giant Hurt/Comfort Fic. The manga is better story-wise (and, you know, complete), but the anime is better spiritual ice cream binge material.
For that matter, what about the ending of the manga, after Tohru and Kyo hook up? Folks pair up with the people they've been in love with, the Zodiac curse is broken so they can show affection, we see that Kyoko was reunited with her husband in the afterlife, Akito is able to move on, and Tohru and Kyo end up Happily Married.
The Read or Dream manga is very much a Lighter and Softer version of Read or Die focusing on the everyday life of the Paper Sisters, three characters who interact excellently and very obviously care a lot about eachother. As a result the series consists entirely of this. The same goes for large parts of R.O.D the TV.
Nia. She's one of the only Moe characters who doesn't invoke revulsion from hardcore Mecha fanboys, partly because she's in one of the greatest recent mecha series, and partly because she's just too cute and sympathetic to hate. She gets even cuter in the dub, where Starfire voices her.
Most of the protagonists are like this. Even Leeron. EspeciallyLeeron.
But watch out for grains of Nightmare Fuel, such as the arm in Episode 20, Charles dying, Eureka getting petrified, Eureka pre-evolution, Hap sitting on the toilet naked, Coralians, typeZERO's rolling eyes, Anemone eating jam... Yeah, just be careful with it, ok?
The Power of Love and The Power of Friendship are central themes in Sailor Moon; when they're not fighting monsters, they're just teen girls hanging out, and some funny moments and sweet scenes of conversations between the girls are Sweet Dreams Fuel. Its humor is a good thing for it, and then sometimes Off Model-wacky art style adds to its charm to some.
Anytime a Code Geass character does anything genuinely sweet or romantic. Also, anytime Lelouch actually smiles for real (and any fanart that shows him doing so counts as well). And, any (non-violent) scene of any character(s) as a child/children!
Windy Tales. A few kids learn how to control the wind, and have fun playing with it together. Cats can fly. Girls can float. The bond between friends is nigh-unbreakable. Soft, relaxing music. A gorgeous, highly experimental art style. All wrapped up in one Thirteen Episode Anime that shows both the bitter and sweet sides of growing up—but likes to lean toward the sweet.
Kamichu!. A Slice of Life about an ordinary middle school girl who becomes a god, and lets her life continue mostly as usual. The characters actually look and act their age, there is pretty much zero fanservice, and the backgrounds are pure Scenery Porn. Any conflicts that arise are resolved within an episode, and several things happen just because they can—a WWE-esque cat wrestling match? Sure, sounds like fun. Amazingly relaxing.
Mokke. The relationship between the sisters Shizuru and Mizuki is so heartwarming, and even their realistically portrayed occasional bickering can't put any dents in that. Sure, some of the ghosts are scary, but in the end their appearance only seems to enrich the two girls' lives.
Don't forget the shrine maiden's song. While the lyrics are somewhat dark, the singing itself is beautiful. It's an in-universe example, too, calming troubled souls.
Hanamaru Kindergarten. It's... oh, my God, if you could weaponize cuteness, this show would be freakin' lethal.
Digimon Tamers is dark, but also outdoes the other seasons in terms of sheer cuteness factor. Culumon is just... It has to be among the most "awwwww" inducing critters. Guilmon's personality is utterly adorable outside of battle, Terriermon needs not be said ("Moumantai~"), Lopmon's frown doesn't make him less cute, and then MarineAngemon is introduced. Cuteness overload.
Minami-ke deserves mention, a funny and cute series involving the love of three sisters and their daily lives in their own schools and as a family. Full of funny moments and heartwarming moments as well.
While Magical Girl Lyrical Nanoha has its darker moments, the show simply has such strong themes of forgiveness, second chances and acceptance that it ultimately becomes this.
Oh My Goddess!. Anhonestlyromantic couple, three truly close sisters, and a sweet, homey feel add up to over twenty years' worth of warm-tea-with-honey feelings. The five-episode OVA alone will fill you with amazing feelings.
Kimi ni Todoke: shy, socially awkward girl with low self-esteem gradually opens up and makes loads of great friends thanks to the influence of the nicest most-popular-boy-in-school you ever saw... and she does it without having to change who she is. It's adorable.
Angelic Layer, a lot of the music in the anime will easily make you smile and the main character Misaki Suzuhara is simply adorable and lovable. Seeing so many people from different walks of life become friends thanks to her and the Angelic Layer game will bring a smile to anyone.
Wandering Son. Behind the constant Tear Jerker moments is a cute, inspiring manga about two kids who just want to be themselves while being adorable.
Tamayura. Four girls on their quest toward adulthood, following their dreams, all while enjoying springtime in their beautiful seaside town. It makes one want to move to Takehara just to enjoy the view every day.
Chobits. Some parts of the series are admittedly veryserious (and, well, perverted), but most of it is the adorable antics of cute robot girls and a couple of intertwining love stories. What really makes it Sweet Dreams Fuel, though, is the atmosphere: the visuals are soft, pretty, and mostly pastel-colored, and the soundtrack alternates between sugary-sweet and soothingly peaceful.
Edward Elric: There's no such thing as a painless lesson. They just don't exist. Sacrifices are necessary; you can't gain anything without losing something first. Although, if you can endure that pain, and walk away from it, you'll find that you have a heart strong enough to overcome any obstacle. Yeah. A heart made fullmetal.
Mahoraba is a funny, heartwarming and strangely weird Slice of Life where every chapter is guaranteed to make you go "D'awwwww!" at least once. The characters are all absolutely adorable and the ending wraps everything up like a big hug in a warm sweater.
A Little Snow Fairy Sugar certainly qualifies. The night I began watching the show, I literally dreamed that Saga was playing my favorite songs on her piano with Sugar right next to me.
The anime version of THE iDOLM@STER. Almost every episode has An Aesop and leaves you with a good feeling about their world.
Ristorante Paradiso. Yes, it's a show about a damn near Mary Suetopia of a restaurant. Yes, said restaurant is called "Cottage of the Bear." But it's so sweet and nice that eventually you give in and get your sugar addiction on. My particular favorite episodes are the birthday parties of one of the chefs' son and the owner's wife.
Fairy Tail. This show, which is about a group of wizards fighting evil, is totally awesome and filled with heartwarming moments. It makes me really happy and never fails to bring on the "aww!" moments.
Girls und Panzer. Power of Friendship? Check.note Look at how Miho's new friends stand for her, and how she manages to fight her inner demons to return their friendship. And that's episode 1. Then they start deepening their friendship.Awesome Music? Check.note Katyusha, in Russian, song by all the seeiyu.True Companions to the second power?note Every tank crew is a group of True Companions, and the whole team is a hugeTrue Companionship. Check x check. Underdogs Always Win played straight but in a non-cheesy way? Check. Values Resonance? Check.note Heroes valuing fellow players' lives over victories at competitions; mutual respect (as explicitly opposed to unidirectional demand of such) betwen family members; team work AND individual initiative being both recognized as important... Sportmanship? Fair play? Fun for fun's shake? A Badass Creed that happens to be a statement of all the former, as opposed to conventional ass-kickingnote This is Tankery! It's not a war! Your tank will cry if you are a bad person! - even if maintained by one more than able to kick your ass? Check. Generaly uplifting story? Hell, check. Humor based on taking a totally Crazy Awesomenote C'mon, it's GIRLS AND TANKS premise and playing it completely straight without taking itself too seriously? Check.
Hyperdimension Neptunia The Animation is an easy candidate with constant laughs and just heart warming moments. Every character will try to make you love them and just wait until the absolutely hilarious and adorable Peashy shows up.
While not an anime or manga series, the Japanese stop-motion series "Komaneko" while short is pretty cute and relaxing which stars a male cat.
The 1980's anime Maple Town stars the adorable bunny protagonist set in a peaceful town featuring various animals.
The Sylvanian Families OVA has a very adorable setting which focuses on a few animal families such as bunnies and cats.
The Anime Yuri!!! on Ice is about a Japanese and Russian figure skater with the same name both striving for the attention of their world championship winning coach. It's really a big game changer in sports anime as we see Figure Skating, a traditionally feminine sport being presented as something incredibly beautiful to watch and have the 3 male protagonists not be derailed and poked fun of for pursuing it as a professional career.
It also portrays a healthy same-sex relationship which is a heavy focus of the show, and the show doesn't use it for fanservice either, but instead to develop and give depth to the main characters.
Yuri Katsuki, the main character, suffers from a crippling form of anxiety which drains him from his passion for figure skating. With Viktor's help, he ends up becoming far more confident, strong and passionate than he ever was, which is a heartwarming development in itself, specially to viewers who have experienced anxiety.
Osomatsu-san. It's hard to believe a series about sextuplet NEETs would be this, but it is. It's a comedy series, the art style and colors are really pretty, and the Matsuno brothers are super cute! No joke, these sextuplets will ruin your life, but in a good way.
Miss Kobayashi's Dragon Maid, despite its silly premise, is ultimately a story of family, and pretty much any scene where Kobayashi is acting motherly for Kanna is bound to bring smiles.
My Hero Academia: The story often goes to dark places, however, it still manages to be this due to having Midoriya as the main character. This is, after all, a story about a boy with a Dream-Crushing Handicap that decides to never give up and strive to fulfill his dreams despite everyone saying that he would never make it, inspiring everyone he meets to work even harder and try to be better, including his own childhood hero. To make it better, the Foregone Conclusion states that he succeeds in becoming the best hero.
All Might: The time I fought All For One at the Kamino, that's when I thought "here is the goal". But there you were. You... a timid, quirkless boy who day after day rose to meet my expectations! And day after day, I whispered to myself to keep on living. And then, your mom even told me "live on and protect and nurture him!", and even now I am clawing on! You changed me!! I am alive! With this hand of mine, I'll twist fate into whatever shape I like!
Not only is Amanchu! a very easy-to-watch/read slice-of-life with inspirational characters and beautiful scenery, the chibi facial expressions and animal mascot are adorable.
Flying Witch's interesting fantasy world, heartwarming family scenes, and cute cats are sure to fuel some nice dreams.