"Please tell me who I really am."

This e-mail message was sent by Mika Kimoto, an editor working at a publisher in Daiba, Tokyo.

Coming from a wealthy family, Mika has always had everything she has ever wanted and more. She is a third-generation Korean living in Japan. She loves her job, and her Japanese boyfriend is a doctor.

There's one thing that bothers Mika though... Her father Masao is very conscious of his ethnic heritage and will allow Mika to marry only a Korean. When her relationship falls apart because of her father's interference, she just happens to post the above message on a mobile phone dating service.

Ryosuke, a blue-collar warehouse worker at Shinagawa Pier, replies to Mika's message.

Daiba and Shinagawa Pier are separated by Tokyo Bay.
Mika is a career woman working at a major firm.
Ryosuke lives a meager life doing manual labor at a warehouse.
There seems to be nothing in common between the two. Still, destiny brings them together.

One day Mika happens to find her late mother Yuri's diary. Written within is the tale of Yuri's concealed relationship with a Japanese man before she married Masao. Mika finds out her mother's hidden past and her passion for the man she loved. Without knowing it, she is about to follow the same path as her mother.