Something like Highschool DxD, although it doesn't HAVE to be a harem or comedy (but totally can be), just any manga where the main female love interest is a confident sexual woman like Rias/Akeno, most mangas go for other female character types like Tsun/kuu/yandere and the onee-san is just there for boob filler.

Edit: and to clarify, when I say "onee-san" I'm talking about a character type, not an actual older sister.

Maji de Watashi ni Koi Shinasai!?

~4400 manga completed
~1700 ongoing...

Sorry I should clarify. I want a Male MC but the female main love interest to be as stated above.

The senpai from the second volume of Koaka Head could fit (probably), but the manga had no updates since forever.

The male lead didn't fall for her though

Guess I should clarify too then 😀

While the description make it sound like Kawakami Momoyo is the lead is actually a guy named Naoe Yamato...

That big-boobed lady in the back of the cover (Kawakami Momoyo) is the male mc:s main love interest (actually, he even calls her "Nee-san").

At least in this manga he ends up with her in the end, sort of anyway.

~4400 manga completed
~1700 ongoing...

Oh ok, description on the manga made it look like she was the lead. Thanks.

And Jahu I appreciate the response but would only like manga where the onee-san IS the main love interest, as in when the male lead goes for her.

Kono Onee-san wa Fiction Desu!?

Reading that and it's good, but I'm looking for more of the character type, and in that manga the younger male is the mature one.

If you're ok with light novels, Risou no Himo Seikatsu (Novel) should be worth a shot, the female lead should fit the bill nicely (might not be obvious from the start).

I've only read the web novel version and it was a bit smutty. I don't know how exactly the LN compares to it, but I have reasons to suspect it's a tad more smutty...

Light novels are fine and i added it to my reading list. Thanks.

Any more suggestions, especially manga are welcome.

14-sai no Koi side couple between male student and female teacher. The female teacher has that "ara-ara" personality and tease the male student a lot. I thought it probably fit.

Wow, 14-sai no koi was put onto my wishlist a long time ago.

Guess it's time for me to read it. Thank you.

Keep em coming if you know them.

Edit: I missed where you said "Side couple". Reading the manga now and it's fantastic but still would like a MAIN couple like that. Thanks for the fantastic recommendation regardless though 😁

Here are a few :
Tasogare Otome x Amnesia
Anedoki
Natsu no Arashi!

If you're OK with teasing without real romance maybe Jormungand... The female does seem interested and teases the MC but nothing really happens.

Thank you, Amnesia was on my wishlist as well incidentally. Had not heard of anedoki and Arashi was a Shaft anime but I hadn't watched it yet. Will add to reading list, much appreciated.

Medicine it should meet your requirement. its only oneshot though 😛