WalkerRed

The story revolves around Sei Iori, a young Gunpla Builder and student who has a dream of becoming the best Gunpla Fighter in the tournament and someday become as good as his father. As the only child, his family owns a small Gunpla shop and his talent is well-honed, however his weak piloting abilities have led him to a series of first-round losses.

Yukiteru Amano (or Yuki) is a loner who never really interact with people and prefers writing a diary on his cell phone with his only companion being an imaginary friend named Deus Ex Machina, the God of Time and Space. However, Yuki soon learns that Deus is not a figment of his imagination but real when Deus makes him a participant in a battle royale with eleven others.

The second season of Kuroko no Basket

Kuroko is a member from the legendary middle school basketball team known as "The Generation of Miracles", and while nobody seems to know about him, the main 5 players of the team all admit that he is a better player. When he joins the high school basketball team, everyone is surprised to find out that he is small, weak, and easy to miss.