Vocaloid vanilla doujinshi with a bit of a twist in the setup. Len has a sister complex towards Rin. One day Kaito happens to catch him masturbating while thinking about Rin, and now Len won’t be content until he knows that he’s adequately paid for Kaito’s silence. Two guesses as to how he goes about it. Pretty cute and vanillaey, and, of course, Len-kun pretty much defines delicious trap!