so how did we get to this point? Onii-san is reading a script (assumedly to help Akira practice) and then Satsuki just rolls up from the back and whips it out? But his pants were all the way down? Was Onii-san just practicing naked?
This one just seems strange, it's presented like he was just reading the script and she decided to start playing with him, but the dude isn't even wearing pants. Either she already took his pants off and he's still acting surprised at what she's doing, or he just reads scripts with his hog out. Seems like he should still be wearing pants but just be unzipped or something.