I Kept Pressing the 100-Million-Year Button and Came Out on Top, Vol. 5 (manga)

Shortly after they return from the joint summer training camp with Ice King Academy, Allen and his friends are suddenly called to Lia's homeland-Vesteria. There, they're told by Lia's father, the King of Vesteria, that the end of Lia's study abroad has been decided...! Will Allen be able to change the king's mind before Lia transfers away?!