My Girlfriend Was Stolen From Me, but I Was Trained by the Four Heavenly Kings of B*tchy Gals at School (Including My Childhood Friend) and Before I Knew It, I Had Become a Monster

The beginning of the story is a standard NTR development. From there, the main character is sexually matured after a messy summer vacation with his childhood friend and the b*tchy gals. What decision will he make when his ex-girlfriend comes crawling towards him, urging him to get back together with her….. The story itself is an absurd gag with a lot of pointless jokes, so it is a romantic comedy in genre, but the comedy element is low. *Contains a lot of s*xual descriptions. Please refrain from reading if this is uncomfortable. Also, this world is very similar to the real world, but only the flow of time is 10 times different. One year in that world is equivalent to ten years in the rea...