I want to read more about manga with romance but has boxing theme and male lead is boxer even it not has many boxing match like Open Sesame

But Female lead is not boxer(Muscular girl is not my type)

Punch! is pretty much what you're looking for.

[img]https://i.imgur.com/6MBFpsv.png[/img]
ᵂᵃʳᵘᶦ ᴷᵒᵗᵒ ˢʰᶦᵗᵃᶦ ᴳᵘᶦᵈᵉ | ᴳᵉⁿᵉʳᵃˡ ᶦⁿᶠᵒ | ᵂᵃʳᵘᶦⁿᵉˢˢ

Quote from Bog Initiate

Punch! is pretty much what you're looking for.

I read that manga before but thank

Hajime no Ippo might be worth checking out. There's romance pretty early on, but the romance is secondary to the action. Shoujoesque manga with fighters seem uncommon, so you might want to consider fight manga with romance and drama instead.

You could try 1 Pound no Fukuin by Rumiko Takahashi.

Quote from M00nWater

I read that manga before but thank

I remembered some other titles that you might find interesting. They also fit with your description (and are shoujo).

There's a oneshot included in Kindan by OSAKABE Mashin. It's called Something that is so hard to say (Vol.1, Ch.6).

There's another one included in Namida ni Nureta Koi by ABE Tsumika. It's called Black Light (it's the 2nd story). This one contains mild nudity

[img]https://i.imgur.com/6MBFpsv.png[/img]
ᵂᵃʳᵘᶦ ᴷᵒᵗᵒ ˢʰᶦᵗᵃᶦ ᴳᵘᶦᵈᵉ | ᴳᵉⁿᵉʳᵃˡ ᶦⁿᶠᵒ | ᵂᵃʳᵘᶦⁿᵉˢˢ

How about Katsu!?