「リアルな勃起チ○ポを描く為に必要なの！」ボクの姉はエロ漫画家。しかし、男の体を知らないようでいつも男の体はアシスタント任せ。しかし、そのアシスタントも処女しかいないので、姉の仕事場のマンションに呼び出されてはボクの体は参考資料に！
"I need this to draw a realistic erect penis!" My sister is an erotic manga artist. However, she doesn't seem to know anything about the male body, so she always leaves it to her assistant. However, the assistant is also a virgin, so when I'm called to my sister's apartment where she works, my body becomes a reference material!
