Ok, Masaki went on his trip, left her with Shingo then came back in that night, kissing her in the playground which misled her thinking it was Shinjo acting as Masaki by using Masaki's kiss style. Shingo went inside home, realising him home with her, both already undressed, then Shingo pulled himself back from opening their door because she loves Masaki not him. Now, last chap, Masaki and she were half dressed not wholly undressed like last time which means another day. And then, here was that comment I quoted below:

Natsume1's: "i think that the one she really slept with was shingo and not masaki......if u notice he took the lights off in the shower and even put soap in her eyes....plus when he barged in asking how long shes gonna stay in the bathroom that was alot more like shingo than masaki i really think that she thought she slept withmasaki but only at the end realized it was shingo."

Back to my theory, that gang rape where Masaki turned off the light while Shinjo did her, as the threesome. I thought it could be Masaki's style, or it cold be purely in the heat of the moment.

Now, Natsume's comment is totally plausible. It was she who thought it was Masaki that whole last chapter, while Shinjo concealed everything until last scene where his hair and scar gave away who he really was. She being cuddled by him with her sweet eyes in prior scene, and in last scene, her eyes changed. It was she realised who he actually was, with her thoughts doubled it down: "I didn't think I would betray someone I love, so fast."

started with a bit of comedy with a girl with huge breasts... Then it quickly turned annoying. First off I can't stand the younger brothers personality.. In fact I think it's cause it reminds me of my ex lol .. Second she is just a no good slut through the whole entire thing.. And it ends with her saying she loves one but can't even take 1 night let alone 11 away from him so she spreads her legs for the second.. And the younger brother is a fucking prick. End of story . Left me feeling pissed and annoyed. And all other side stories were rushed and incomplete as well

especially that scene in volume 3 when they both go at her and turned of the lights that was some serious gang rape going on there. THAT IS NOT OKAY.

if a guy like that would threaten me to end the relationship just because i wouldnt have sex with him the day we started going out i would tots think he's crazy, come on now, i know my worth. this guy is mental

started with a bit of comedy with a girl with huge breasts... Then it quickly turned annoying. First off I can't stand the younger brothers personality.. In fact I think it's cause it reminds me of my ex lol .. Second she is just a no good slut through the whole entire thing.. And it ends with her saying she loves one but can't even take 1 night let alone 11 away from him so she spreads her legs for the second.. And the younger brother is a fucking prick. End of story . Left me feeling pissed and annoyed. And all other side stories were rushed and incomplete as well

i think that the one she really slept with was shingo and not masaki......if u notice he took the lights off in the shower and even put soap in her eyes....plus when he barged in asking how long shes gonna stay in the bathroom that was alot more like shingo than masaki i really think that she thought she slept withmasaki but only at the end realized it was shingo

Who did she sleep with? Does the ending imply that even after making love to Masaki, she actually wished it was Shingo? Or was it Shingo to begin with? Did Masaki really come back for her? Or was it actually Shingo? But why show Shingo coming home and finding Masaki's luggage? So what's the big deal? Argh!!!