Top 2 in Top 10 Best School Romance Anime From Friendship To Love.
Natsu no Arashi!
Natsu no Arashi! is a manga series created by Jin Kobayashi, who is best known for his earlier work in School Rumble. Shaft adapted the manga series into an anime series directed by Akiyuki Shinbo. The plot revolves around 13-year-old Yasaka who stays at his grandfather's house during summer vacation, where he meets a young 16-year-old girl named Arashi in a water bar and applies for a job there.
But in essence Arashi is a soul who can travel through time, she also has other soul friends who have the same ability. Yasaka and Arashi have taken many timeless journeys together to solve something and mess things up rather than solve it.