University student Mizuho Suga ( Tsubasa Honda ) learns that her former high school classmate Haruka Origuchi ( Erina Mizuno ) died from an illness. At her funeral, Mizuho meets another former high school classmate Hikaru Narumi ( Yuma Nakayama ). In their high school days, Hikaru Narumi was famous for being a playboy. Mizuho and Hikaru Narumi were also in a special relationship. Hikaru was outgoing, but Mizuho found it difficult to make new friends. They once kissed in the classroom and went on a one day summer trip together. They weren't friends or lovers and kept their relationship a secret. Meanwhile, Haruka Origuchi's mother tries to talk to Mizuho, believing Mizuho was her daughter's best friend. Haruka's mother asks about Haruka's boyfriend. Haruka became pregnant with her boyfriend in the past. - AsianWiki