Kinosuke Amano is the second son of the Lord of the Mikazuki clan, based in a lush green village nestled among mountains in Kyushu. He is a free-spirited youth, who slips out of the castle every night and is enchanted by looking at the stars. One summer, on the night of Tanabata (“the Evening of the Seventh”), Kinosuke encounters Sen, a girl from Hotaru Village, and Genta, her friend from childhood. Together, they assemble a turret for observing the stars. From that day onward, Kinosuke, Sen and Genta are friends, transcending social barriers, as they spend long hours every night searching out the stars. Kinosuke and Sen eventually fall in love. However, the time arrives when they must be apart.