You can find a machine translated English version of the game here:
https://www.hemdomblog.com/2021/10/succubus-battle-simulator.html
Each floor in the game introduces a new type of enemy, and each enemy has two different attacks in battle and one scene somewhere outside of battle. The enemy that pertains to kissing is on the top floor, floor 10, and her scene can be found at the very end of the floor.