Yuna Aikawa, who is good-natured and cannot refuse people's requests, was forced to work overtime as usual, taking her work home with her.
Masaki, Yuna's husband, was worried about her, but Yuna smiled at him and said, “I'm Ok.” Masaki did not take it well.
“I’ll punish you.”, “Bad girl Yuna.”, ”Bad girl needs to be punished by spanking.” Yuna is puzzled by the first time she was told these words.

“I've been told I'm an honor student and a good girl...”
“Really? Isn’t that you are someone who is easy to exploit?”
Masaki’s painful word deeply penetrates Yuna’s heart.