This is a story of a beautiful, romantic and thrilling summer somewhere in the east. 14-year-old Sybilla arrives in a sleepy little town to spend her holidays with her aunt Martha. She falls in love with Alexander, a 41-year-old astronomer taking care of the old observatory. No wonder he considers her too young for romance. Meanwhile, his son Mickey, also fourteen, falls madly for Sybilla. She promises Mickey one hundred kisses before the autumn. But he only gets 73.