Aitsu no Kanojo

The mc is getting pushed around by everyone and man, there's so many red flags. Why is someone else's girlfriend seducing the mc and no one tells the mc either what they're hiding. Just get the mc together with another girl bruhhh, at least that girl is honest and not deceiving or hiding anything from the mc. The author is just keeping us blue balled, this is a guilty pleasure manga for me ngl. It's so toxic and fked up but i can't help but want to know what's gonna happen and what the other characters are hiding from the mc. I swear if it's some wack ass reason.....

The artist is good but the plot is shit

Like after chapter 2 i couldnt take this seriously. Like the gf of a friend is trying so hard to make mc jelous cause she secretly loves him, but whenever he accepts her advances, she pussies out. Only when a rival appears does she stop playing her shitty tricks on him however he chooses not to do shit with her.

Honestly hard to like. If i was mc, i would tell the gf lady that if you want to be with me, break up with ur bf, i refuse to date people who are already in a relationship

stay away, currently japan culture is infected by NTR virus.
don't even hope any good ending in this kind of manga.

Well, it isn't, for now

One thing I did confirm after going through all the reviews - never judge a manga by others' reviews. I personally am absolutely loving this manga. Yes true, some strange stuff is indeed brewing but the fact is that the MC is getting all the graces. The female lead is indeed going out with the best friend but it gives off the feeling of being obligatory. The reason I don't give this a 10 is because I still don't know how this is gonna turn out. Well, let's see. I am having an absolute blast as of now.

Highly recommended!

Seems the girlfriend isn't the only one waving red flags. Turns out his friend might also have his own red flags the MC should look out for.

It's looking more and more likely the friend is

just dating his GF out of a fucked up sense of rivalry with the MC, with whom he appears to have a severe inferiority complex with.

Regarding this

inferiority complex: if the friend noticed early on the girl liked the MC, that would mean to him he is "losing" to the MC if they started going out, so it's likely he asked her out before MC could realize her feelings. The girl, being close to them both and seeing MC apparently uninterested, starts dating the friend. Either to get him jealous, or she's taking her chances with someone she thought actually liked her.

I wouldn't be surprised if it turns out later

the friend also took or tried to take "all her firsts" early in their relationship not because he's attracted to her but just to have more and more things that he's "won" over the MC. Might explain why she grew cold to her "boyfriend", when she realized that he didn't really love her and was just using her to scratch his fucked up rivalry itch. Now she's coming on to the MC, because 1) she liked him originally and maybe 2) to get back at her "boyfriend" for pulling this shit on them.

I wouldn't trust them both. Better run. Just. Yikes.

Not the worst but looking like the ol "I dated the friend cause I wanted to make you jealous and for you to want me more" trope. So far not really much characterisation and not much info about the triangle thats happening. 5/10 as a result.
Also the name of the series is kinda off? Why Someones Girlfriend when it's his best friends?

to ch4 edit

So yeah it's really looking like it's the old "I dated the friend cause I wanted to make you jealous and for you to want me more" trope and that just makes the character motivations/actions make the least sense.
If MC has always had a crush on her then why did she date the best Friend if she wanted to be with MC? Why continue to be with best friend if the MC is showing interest now? This feels like NTR for NTR's sake and not for good writing reasons. This series is starting to fall apart already as a result and I'm actively not rooting for any of the characters as the best friend also seems to be a douche or in the least not what he really seems.