Boku Dake no Romantist

Shinobu Aizawa is already in his forties, but he works part-time as a security guard while pursuing his dream of becoming an archeologist. One day, he is sent to work at a party venue and the guy he tries to hold down for making a fuss turns out to be Aldo, the very prince who organized the party. Before Shinobu has a chance to understand what's going on, he's being dragged into the center of the room and introduced as the prince's fiance! This is a romantic love story between a bold and brazen prince and a middle-aged dreamer by the popular manga artist Nerima zim! (From Renta!)