Found at Hentaicore, I believe these are the tankoubons scans, even so the covers were missing. I added the ones found on amazon.

The story was serialized in Young Comic between the 2011-06 and 2012-04 issues, which are all missing at the moment.

Dimwitted girl becomes the new girlfriend of the womanizing older brother of the MC, even though she's interested in the MC, and the MC has had feelings for her for a long time. The MC tries his hardest to cockblock his bro and gets the girl to have sex with him via the trusty "let me teach you about sex by practicing it" trick. After various things, the MC and the girl are finally together and eventually marry. Happy end.

Take out chapter five, where the girl has sex with her boyfriend (which ironically constitutes the "netorare" part), and it would be like a pure love story.

@Nanaya2007
The MC was in love with her and she was interested in him. They knew each other in the past. The reason why she started dating his brother in the first place was because she thought he reminded her of the MC.

Base +24, EdoubleT +7, DCH268 +6, dakight +8, gurumao +11, Ensei Sohryu +6, fidazzle +8, psyburn21 +16, ichikku +14, Lalilulelo04 +3, RyogoTM +11, 8jposfolifas +7, rext11 +3, and 1 more...

Meh. Family Restaurant did it better.

Base +6, Bane13 -31

Thanks, i like it.

Base +9, ShinKagami +8, Bane13 +31, stupid army +6, Colonia +5

Umm... what's pure about teaching your brother's girlfriend sex by having sex with her, knowing that she's your brother's girlfriend? Even if you remove chapter 5, you're still banging someone else's girlfriend and cockblocking them at the same time.

Pretty sure none of you would enjoy your "bro" cockblocking you and then actually stealing your girlfriend from right under your noses. I have no idea how this is pure. The guy deceives a girl, then makes her fall in love with him. If that was a fat guy doing it, no one would say this was pure, much less a love story. The ending itself is technically speaking an NTR end. Netori, yeah, but still NTR.

@freudia
It's like a telenovela plot. It certainly isn't pure love story because of the added dimensions muddling things up, but it was a good NTR end, after all, MC ends up saving the heroine. Still, the heroine should never have dated the older brother in the first place, in my honest opinion. Then again, we wouldn't have this hot manga if that was true, would we?

The lightsaber censoring is pretty irritating, however.

@BillNine10
I'm sorry, but the Japanese barely differentiate between netorare and netori when they label something as NTR.
You go to Japanese discussion boards, blogsites, even videos of TV show streams, and whenever someone steals someone from another person, they call it NTR and they use it broadly for netorare or netori. Even in Seitokai Yakuindomo season 1 episode 12, Yokoshima-sensei says she'd like to netori her friend's husband, and the following eyecatch is N-T-R! N-T-R! N-T-R!

If you check Sena Youtarou's Kannou Triangle and read it in the original Japanese, NTR is read as netoRU, not netoRARE.

This is because NTR, to the Japanese, covers netorare, netori, and netoru. It's the same verb, different conjugation.

Base +6, Wilfriback -6, Chamma +5, Dark-wings +1, stupid army +6, plester +4, bintanghitam +1, MKCyrax +7, Long1 +5, DattacK +6, 889zas +5, Buraku-chan +9, Colonia +5

Well in chapter 5, the girl just punishing herself for betraying the brother and try to confirm her feeling by doing that. She was told by her friend accidentally that having sex with someone that wasn't your lover is called cheating.(her friend refering to the brother)

After chapter 5, she also asked what the mc reaction was. It was painful because she already fallen in love with the MC. She also doesn't want to do that again with someone else. She promised MC that she will only have sex with MC only and she want a "lover sex" not "practicing sex" from now on.

MC brother...eventhough he was a cheating bastard (he even acknowledge that he was 5 timing the girl in the end) he also have a good side. The girl said that in the past the brother told her about how MC was very kind but it became too boring for him because the MC always thought that he will never win againts the brother. The girl said that maybe the brother was happy because MC finally confront him for the first time. In the end the brother was an easy-going man, when he tried to have his way with girl again, it was all a ruse for making MC to take action. The brother even order MC to get out from his place.(implying that he want MC to stay with the girl together)

Edit :
it was known that he was a brocon and all this time he deliberately dating the kind of girls that MC would like. He really love the MC's vexing face. He also a little regretful because a girl like that {our heroine) is very rare to find, that is why he can relaxed and just give his little brother to her.

Base +8, Lalilulelo04 +3, ShinKagami +8, Wilfriback +6, RyogoTM +11, 8jposfolifas +7, rext11 +3

NTR is used to abbreviate Netorare and Netorare IS NOT Netori. Still, this story could be argue to be either Netorare or Netori depending on how who the audience identifies with, unlike fat ugly old man NTR where no one will identify with the fat ugly old guy, not even fat ugly old guys THEMSELVES. Personally, I hate the hentai story like this one more than pure Netori.

Base +4, plester -4, bintanghitam -1, wfangjoker -1, kasumi_fans -1, Wilfriback -6

Speaking of cockblocking, what a nice white genitals.

Base +4, Bane13 -31, funk doctor spock +2

A tank with full censorship? Really...?

Base +8