Tennis no Ouji-sama: Message in a Bottle

テニスの王子様 OVA FAN DISC ~Message in a bottle~

Picture drama episode included with Prince of Tennis official DVD fandisc.

Atobe, sneakily, throws a message in a bottle in the river, which winds up next to the Rikkai and the Seigaku regulars.

(Source: Prince of Tennnis Wiki)