勇者に幼馴染を寝取られたので、勇者の婚約者を寝取ろうと思う (Associated Names)

The protagonist, Roush, spent every day happily with his beautiful childhood friend. One day at the age of fifteen, he attended the ceremony called the “judgement”. There, Roush was bestowed a useless skill “Unimportant” while his childhood friend was bestowed the legendary skill “Sword Princess”. The hero caught wind of that and pulled in Roush’s…