Onegai Twins

One of the girls is his sister. None of them know which one it is.

Also known as Please Twins! in English.

A sequel to Please Teacher, Onegai Twins! centers on Maiku Kamishiro, who moves into town looking for his childhood home, shown in a picture of him playing with his long-lost sister. He soon meets two girls his age, Miina Miyafuji and Karen Onodera, who each also have the same picture. But there are only two children in the picture, and neither of them know which is the sister, and they can't afford to have DNA tests run on themselves. To make matters worse, both girls become rather attached to Maiku.

The series, of course, includes appearances by the characters of the previous series, showing how they've fared since the end of Onegai Teacher. It is also notable for being the first work in the long-running partnership/friendship between voice actresses Mai Nakahara and Ai Shimizu.

Tropes used in Onegai Twins include:

• Absurdly Powerful Student Council: Ichigo seems to be in total control of the school, to the point of being able to take a bunch of students on a tropical vacation on student council funds. Or give Maiku a job. Or order the teachers to not let anybody leave the grounds.
• Baker's Dozen: The OVA brings the episode count to 13.
• Blatant Lies: Ichigo, often. Also Miina in this priceless moment.
• Brother-Sister Incest:
  • Though novelization and anime/manga adaptations switch who is the canon, true twin, and chosen girl at the end.
  • Also with Matagu, who didn't have any particular lust for his sister in Please Teacher.
• Catch Phrase: "We might be related! We might be strangers!"
• Demoted to Extra: Several cast members crossing over from Please Teacher go through this, but none more so than Kei -- the poor guy doesn't have a single spoken line (except in the OVA).
• Evil Laugh: Ichigo's delightful "Ufufu", complete with a Cat Smile.
• Fainting: Karen fainting at any surprise or stress is a running gag, though like many such things, it tapers off as the series goes on.
• Fan Service: Truckloads of it, since the two girls share their baths all the time.
• Flanderization: Matagu. He was a pretty normal guy in Please Teacher but has been flanderized into an incestuous creepy lolicon in this.
• Flat Character: Matagu, despite being much more rounded in Please Teacher.
• Friends Rent Control: For an orphaned high school student working to support himself, Maiku's house is pretty big and fancy. Then again, the small-town setting makes this slightly less unrealistic than it would be in an urban setting. It's also explained that Maiku discovered the house in less-than-perfect condition and was able to rent it cheaply.
• Genki Girl: Miina.
• Hidden Eyes^[context?]
• Imagine Spot: All three of them keep having fantasies about each other.
  • Including guilty ones such as Samurai!Karin and Cop!Miina (each by the other)...
• Imagine Spotting: And upbraiding each other over them.
• Indirect Kiss^[context?]
• Legal Jailbait: Morino Ichigo, 21 years old and stuck in the body of a 15 year old after spending 6 years in a coma.
• Little Miss Snarker: Ichigo Morino, as mentioned above.

Mizuho-sensei: What are you doing?
Ichigo: "Birdwatching"
Mizuho-sensei: You're lying, aren't you?
Ichigo: Well of course I am.

• Mistaken for Gay: Because Maiku hasn't been ogling them, Karen and Miina worry he is gay... so they crank up the Fan Service level to try and get a reaction out of him.
  • Classmate Kousei Shimazaki is constantly, constantly flirting with Maiku, on top of being the closest thing he has to a friend at the school, doesn't help matters. Karen and Miina might not have mistaken Maiku's sexuality at all in not for female classmates fantasizing about Kousei and Maiku as a couple.
• Nice Hat: Karen has one.
• No Periods, Period: When Karen is brooding over her revelation, the other girls assume that it is her time of the month.
• Nosebleed: Poor Matagu!
• Not What It Looks Like: Karen just fainted and fell face first into Maiku's lap, honest!
• Older Than They Look: Ichigo, as described under Legal Jailbait.
• "On the Next Episode of..." Catchphrase: "Next time, more twins!"
• Orphan's Plot Trinket: The photograph of the twins.
• Plot Based Photograph Obfuscation: A convenient hat obscures the face and hair color of the girl in the photograph.
• Pretty Freeloaders: Miina and Karen qualify as this until they get roped into attending school and working.
• Scenery Porn: for those who like small-town Japan.
• Shrinking Violet: Karen.
• Title Drop: Both parts of the catchphrase listed above are episode titles.
• Tomboy and Girly Girl: Miina is the tomboy, Karen is the girly girl.
• Twelve-Episode Anime: Like Please Teacher, Onegai Twins are a twelve-episode anime and a one episode OVAs.
• Twincest: Averted - no actual sexual contact occurs between any of the three main characters until they figure out who is the real twin. Until then, it's only affectionate hand-holding and light kissing (although kissing is pretty serious in Japan).
• Two-Teacher School: Lampshaded when a student mentions that it seems like the school only has two teachers: Kazami Mizuho and Yamada Masaomi.
• Victorious Childhood Friend: The girl who isn't the twin.