Manager, do you know about my husband's promotion? Director Han told the head of the planning department, Ji Xianyu and Zhang Mingzhu, that if one of them cannot be promoted, they must leave the planning room. There are rumors that Zhang will use his weakness towards women to lobby Han for promotion. Xuanyu is very anxious. He tried to attract Han, but it didn't really have a significant impact, so he called his ex girlfriend Ji Hui. He called Han home and introduced him to her. Han was completely captivated by the seductive Ji Hui. Meanwhile, Xianyu's wife was very unhappy because he blamed her for not getting his promotion, so she went to talk about Han herself...
平凡上班族竹林龙马（田所梓 配音）几乎没有过过一天舒心日子，39岁了还孑然一身，在黑心企业里为贪心的老板做牛做马。终于，在狭窄又潮湿的单身公寓里，他的生命走到了尽头，然而当龙马再度睁开眼时，发现自己竟然转生来到了异世界中，成为了一名年仅8岁的少年。 和凶险的现实社会相比，异世界里的生活虽然辛苦但充满了乐趣，龙马居住在森林里，埋头研究如何利用魔法来驯养野生的史莱姆。个性开朗的千金大小姐艾莉亚莉亚（桑原由气 配音）、喜欢舞刀弄剑的公爵莱因哈特（小野大辅 配音）、善良热情的魔兽使艾莉莎（早见沙织 配音），在这个世界里，龙马很快就交到了朋友。
