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

Allen and his friends find out that Shii is on her way to the Holy Ronelian Empire to be wed in a political marriage. Thanks to a letter Shii left behind, they learn how she really feels about it, and they decide to go after her! But just who can Allen and company rely on to help sneak them into Ronelia?