As Mr. Masao's construction company was struggling financially, he decided to sell it to Mr. Kozawa. However, there was a secret that Mrs. Yurine had been hiding; when their business started to fail, she took out a large loan without her husband's knowledge. When she confided in Mr. Kozawa about their financial troubles, he offered to lend them money under one condition - that she becomes his mistress. Little did they know, Mr. Kozawa had ulterior motives for hiring Mrs. Yurine as his secretary; every day, he would use his tongue like a snake, entwining itself around her alluring lips before devouring her mature body...

夫・正雄の経営していた工務店の業績が悪化し小沢に買収される事になった。正雄は営業担当、ゆりねは秘書として小沢の下で働く事となったが、ゆりねには秘密があった。それは経営が行き詰っていた時、多額の借金をしていたのだ。それを小沢に相談すると、小沢は金を貸す代わりとして愛人となる事を条件に出す。そして、小沢は秘書の日課として、ゆりねの艶やかな唇に蛇のような舌を絡めると、熟れた肉体を貪っていくのだった…。