Happy Lesson(2002)

Happy Lesson is a comedy anime series about Hitotose Chitose, a 15-year-old boy who moves into his parents' empty house after leaving the orphanage, only to find himself isolated and miserable. His fortune shifts when five of his high school teachers—an artistic cosplay enthusiast, a nurturing homeroom advisor, a spirited athlete, a priestess nurse, and an eccentric science teacher—decide to move in and become his adoptive mothers. As the household fills with their chaotic warmth and competing parenting styles, Chitose discovers what it truly means to belong to a family. Each woman brings her own quirks and wisdom to his life, while also welcoming his two sisters into their unconventional home. Through their constant attention and care, Chitose learns that family isn't always traditional, and that the noise of love matters far more than silence.