While in college, Keita Hasegawa worked part-time at a nursery school, which motivated him to join a publishing company to get involved in children's entertainment.
As an editor of children's books, he has created books in a variety of genres and for a wide range of ages, including board books, picture books, novels, comic books and so on. In the last few years, he has been involved in character (“Oshiri-Tantei”) branding and animation production, along with editing books. Hasegawa has also recently participated in some Fellowship Programs in Seoul and Frankfurt, making presentations introducing the Japanese IP and its market.