Suzu Momose is a 28 year old and virgin. She has been in love with a handsome university student, Hoshina, who works part time in her department. Suzu wants to tell him how she feels before he graduates and gets a full-time job in the spring. Surprisingly, Suzu finds out Hoshina has liked her, too, but their first sex doesn't go well..."Are we sexually incompatible...?" It troubles Suzu, so her colleague Sasazaki tells her, "Why don't we practice?"
「…私たち、エッチの相性悪いの？」
――百瀬涼はズボラで男勝りな性格。気づけば２８歳、未だ男性経験ナシ。
けれど実は、同じ部署のイケメン大学生バイト・保科くんに３年前から片思い中。
春から新社会人の彼と一緒に過ごせるのもわずか。思い切って告白したら、まさかのＯＫが!?　
「愛液でヌルヌルですよ」彼の手慣れた愛撫にトカされてく涼。
ところがいざ本番、保科くんのが何度シても入らない!?　
…焦る涼に、同期入社の笹崎が「俺とシてみる？」と持ちかけてきて？