Teman sekelas yang lebih tua ingin bercinta dengan pacar saya - part.1

Mizuna gets fucked! I was a bully when I was young, but I got a job at a prestigious company. I am now living together with Mizuna, whom I promised to marry, in an apartment. The other day, for the first time in many years, a senior student, who was famous in my hometown for being bad suddenly came to my place. He was going to extort me and hold Mizuna as compensation...