Quite an uncanny person

Characters:
Aquamarine Hoshino (or Aqua for short, and he cold)
Ruby Hoshino (Aqua's twin sister, and very energetic)
(they both blonde and has a star on one of their eye that represents their dead mom)

entire information: https://en.wikipedia.org/wiki/Oshi_no_Ko

You Are in the world of Oshi no ko

Saitama is a self-proclaimed superhero who can defeat every opponent that he encounters with a single punch. He searches for a worthy opponent after growing bored by a lack of challenge in a world filled with superheroes and villains. While fighting evil, he meets his student, Genos.