I Kept Pressing the 100-Million-Year Button and Came Out on Top, Vol. 7 (light novel) — Syuichi Tsukishima

CRASH THE WEDDING, SAVE THE DAY!When Allen learns that Shii Arkstoria has been sent to the Holy Ronelian Empire to enter a political marriage with an abusive nobleman, he and his friends immediately infiltrate enemy territory and stage a rescue operation. But to return with Shii safe and sound, they'll have to face a powerful new member of the Thirteen Oracle Knights. Later, Allen proctors a Thousand Blade Academy entrance exam with a catch: Anyone who can land a hit on him in a sparring match will be admitted on the spot! After that, the arrival of Valentine's Day sends Allen's female friends scrambling to win his affection!