Since their parents died at an early age, Susumu and Yoriko have lived together. Susumu is now 33-years-old and Yoriko is 40-years-old. Both of them have yet to marry. They are like most siblings and they rely on each other. One day, Susumu and Yoriko receive a letter that is sent to the wrong address.
| Actor | Role |
|---|---|
 Osamu MukaiSusumu Onodera | Susumu Onodera |
 Hairi KatagiriYoriko Onodera | Yoriko Onodera |
 Mizuki YamamotoKaoru Okano / Akira Asano | Kaoru Okano / Akira Asano |
 Mitsuhiro OikawaKosuke Kawada | Kosuke Kawada |
 Kumiko AsoYoshimi | Yoshimi |
 Nao OmoriKeisuke Sakai | Keisuke Sakai |
 Minako KotobukiAsako | Asako |
 Tsuyoshi MuroKosuke Kawada | Kosuke Kawada |
 Masafumi NishidaNot listed | Not listed |