I don't think it's based on anything, if that's what you're asking. It' simply a monthly series consists of 2 pages per chapter that's been going on for 5 chapters now in Anthurium. Ch.5 is the latest in the latest issue, 2018-01.
I expect that it's general knowledge now that urushihara satoshi almost never write a full coherent story. He mostly draw sex scene with rough background story written or hinted somewhere. Basically, he's closer to a novel illustrator than mangaka.