Anime with three blue-eyed high school students

Question

I'm trying to remember an anime I watched when I was younger.

There were three main characters; two were siblings, a boy and girl. The third was also a girl. All three of the characters had rare blue eyes. One of the girls had short-ish red hair; the other girl had blue hair, and was a bit sweet and shy. The boy is tall-ish, if I remember correctly.

The beginning shows the boy, holding a picture of his sister and him playing in a kiddie pool, naked, outside the house he lives in now. The characters are all high school students, as well, and I think they lost their mom.

Does anyone know what this anime might be?

Answer 1

You're looking for Please Twins!/Onegai Twins!

Please Twins! is a story about three high-school students: Maiku Kamishiro, Karen Onodera, and Miina Miyafuji. The three were drawn together by a photograph of their childhood home which later makes all of them seek out the house in the picture. However, the picture shows only two children, a boy and a girl. The three conclude from this that only one of the girls, either Karen or Miina, can be related to Maiku. The other must be a nonrelative. The only other identifying feature of the pair in the picture is that the boy and the girl have eyes of the same unusual color, a feature that furthers the ambiguity as all three of them share the same eye color.