1. Aoi Rui
Ai Tenchi Muyo! – Statuesque, curvy, and shy, if Yuki is the brains of the Science Club and Beni’s the brawn, than Rui’s the beauty. She also typcially dons big brown boots and eats a lot, but doesn’t seem to have any particular skills.
2. Acura Tooru
Hitsugi no Chaika: Avenging Battle – While his sister sports green hair and blue eyes, Tooru has the opposite. He also has a somewhat tiresome will-they-won’t-they-they-won’t relationship with Chaika, which hasn’t gone anywhere since they kissed last season (though that was technically a kiss of life).
3. Amira (Demon Form)
Shingeki no Bahamut: Genesis – While in human form, Amira has that cotton candy pink hair, but in demon mode she glows a bright, icy blue. Her moves in said mode are so quick and elaborate that still images are hard to come by.
4. Asada “Sinon” Shino (ALO)
Sword Art Online II – Sinon was relegated to side character in the past Excaliber arc. Like Silica, she chose to be a member of the Cait Sith race, but is armed with a bow rather than a dagger, in keeping with her GGO background.
Cross Ange: Tenshi to Ryuu no Rondo – One part of Captain Zola’s harem which also included Hilda and Roselie, Chris and Roselie now comprise Hilda’s harem. As such, the three are pretty much of one mind on all things, including teasing/hazing Ange. She sports a steel blue hair which stylishly covers one eye.
Akame ga Kill! – Esdeath is one tough cookie, but the immensely powerful, sadistic pale ice blue-haired general still has a soft side, which Tatsumi brings out without fail. I’ve always liked that about her, but the show has made it pretty clear she won’t be joining the rebellion any time soon.
7-8. Hakubi Ryouko & Masaki Sasami Jurai
Ai Tenchi Muyo! – Two-thirds of Tenchi’s household harem, Ryouko and Sasami are highly protective and devoted to the teacher-in-training. It’s also implied they’re not human, but who and what they really are and what their story is isn’t covered in this iteration of the franchise.
Fate/stay night: Unlimited Blade Works – We’ve only seen Lancer in what the industry dubs “blue-filter night”, so the guy may just have shiny black hair, but most GIS results on the guy bring up someone with a dark blue hair, so he’s on this list.
10. Matou Shinji
Fate/stay night: Unlimited Blade Works – At this point in UBW, all we know about Shinji is that he’s rough with his kind, gentle sister, is as a result a bit of an ass, and is voiced by Mr. Despair himself. The rest will have to wait for a Shinji-centric episode.
Orenchi no Furo Jijou – Mikuni isn’t just blue-haired, he’s blue, period. Because he’s a jellyfish. He also looks like a woman.
12. Mizuno Ami, AKA Sailor Mercury
Sailor Moon Crystal – Perhaps the most well-known and venerable character on this list, Ami is a bookish girl whom Usagi eventually wrests from her shell and befriends, then her powers as a Sailor Guardian manifest.
Sora no Method’s resident wish-alien-fairy-mascot thingy, Noel follows Nonoka and the others around a lot, and is closely related to the saucer, if not a manifestation of the saucer itself. When Nonoka brings the friends together, she’s able to manipulate the surface of the saucer to project fireworks, which is neat.
Shingeki no Bahamut: Genesis – Pazuzu is a demon and Azazel’s strong right arm. Still, the blue-haired brute finds that going up against the teamwork of Favaro and Kaisar isn’t something to be undertaken lightly; the humans manage to escape with Amira.
Shingeki no Bahamut: Genesis – Like Gabriel, Raphael is some kind of fancypants angel, but we really haven’t seen nor heard much of anything from her yet. Still, she definitely has blue hair, so here she is.
Susanoo is another massively-powerful character in Akame ga Kill!, but he’s not a human, but rather Najenda’s Imperial Arms. Belying his ability to wreak havoc and destruction upon his foes on a vast scale, the guy’s also an anal retentive.
17. Ureshino Sayumi
Daitoshokan no Hitsujikai – While she may be button-cute, Sayumi the cafeteria girl is an extremely shrewd businesswoman, who doesn’t offer information on the legendary Shepherd without something in return – in her case, having the library club hand out flyers in cosplay.
Akame ga Kill! – Perhaps the most well-adjusted member of he Jaegers, Wave seems like a perfectly decent guy; a Bizarro Tatsumi who has no business being on a team of heartless killers. Still, a Jaeger he is, and what with his big-bro attitude towards Kurome, a Jaeger he is likely to remain.
19. Yuuki Asuna (ALO)
Sword Art Online II – Like Sinon in the latest arc, Asuna has had criminally little to do since being rescued from Mr. SuperEvil by Kirito in the first ALO arc. But she returns to ALO despite her horrible coma experience, this time with blue hair.