If you mean Amatatsu's friends, the ones shown in the first chapter, I think they resemble more Ryou and Yuusei from "Encirclement Love" 'cause Mishiba seems to have, mhm, bangs you could say? While the glasses friend has that upwards-hair like Ryou from EL, although this is just a theory and I see your point
yeah? but when I see these two
http://www.mangago.zone/read-manga/i_m_banging_my_rival_from_a_parallel_world/uu/ibx_chapter-1/pg-16/
and these two
http://www.mangago.zone/read-manga/zombie_hide_sex/nbt/ibx_chapter-6/pg-16/
the resemblance is uncanny, but then again, it’s just a theory tho I like the way this author basically make a sequel with a totally different atmosphere
(=・ω・=)
Another parallel world with two other Sen and Amatatsu in it! Itadakimasu!