Castaway on the Moon (2009)

Seung-geun (Jae-yeong Jeong) is an economically broke man and has just come out of a romantic relationship, he tries to commit suicide by jumping off a Seoul bridge over the Han river, but ends up on an uninhabited islet. Not knowing how to swim and having a flat cell phone battery he cannot leave the island, after the first difficulties in finding food, Seung-geun manages to cultivate a small field of corn. The only person who notices him is Jung-yeon (Ryeowon Jung), a Hikikomori girl who lives segregated in her room. The two begin to communicate, in English, through messages in glass bottles and sentences written in the sand.