The nameable protagonist and his wife Yumi are both 28 years of age and have a young boy and a baby daughter.
The protagonists runs a mountain climbing club but has someday a major accident because of to much sake and has to be transported with an helicopter to an hospital.
This is where the NTR Mystery starts as the insurence agency is witholding the insurance settlement and the young family is now indebted.

[Roughly edited from a netorare blog]