A son-in-law who is drowning in an immoral and intimate life with his mother-in-law who is in her fifties and has a beautiful ass! When his wife is hospitalized, the husband is forced to live alone, and his wife's mother comes from her hometown in Niigata to visit him! After a long time of reunion, the two start living together! Once he is tempted by her soft-looking ass, he can't resist... While his wife is away, their relationship becomes closer!