Amakusa 1637 (AMAKUSA 1637) is a shōjo manga written and illustrated by Michiyo Akaishi. It is about the time-traveling adventures of six modern-day Japanese high school students from the St. Francisco Academy to the 17th century, where they take part in the Shimabara Rebellion. It was serialized in the manga magazine Petit Flower from 2000 to 2002 and in Flowers from 2002 to 2006, and was collected in 12 tankōbon volumes. Source: Wikipedia (en)