"3Ping Lovers! Ippu Nisai no Sekai e Youkoso" follows Tomohiro, a history-obsessed high schooler summoned to the fantasy world of Eunifonia by warriors Alice and Freya. His unique ability to boost female warriors' magic through his semen turns him into a vital hero, as they pledge marriage in exchange for his "power-ups" amid steamy encounters. Joined by allies like Lumines, Lolo, Cature, and Rachel, they battle to reclaim their kingdom from dark forces in this harem-filled adventure.