While it is true that twins (especially identical twins) tend to behave in a more intimate and less physically reserved manner than other siblings, this seems way to much for most cultures and families.
Ps: I tried to rephrase my statement about twins being closer about 20 times and I couldn't make it not look all gross and incest-y, sorry.
^I'm pretty sure its liquid hand soap- there is a brand of soap called muse - they make joking reference the band being soap 2-3 times in the anime - so it would make sense to hire a member of muse to sell the muse soap lol.
(and notice the big hand in nico's pose).
^ Agreed. It looks so far removed from his/her usual style that I didn't notice it was by Kougi until you mentioned it. Just goes to show how good he/she is.