Synopsis
The tennis team from Rikkai University-Affiliated Middle School discovers an unusual bottle while out one day. Inside, they locate a peculiar note that asks whoever finds it to place something inside the bottle and then toss it back into the river. After opening the bottle and removing the message, the team carefully repairs it with tape, adds a few extra objects, and sends the bottle onward. The bottle does not reach its intended recipient, however; instead, it floats to a different location, where it is found by the tennis team from Seishun Academy.
