Well not simply bullied by classmates, peers or whatever. I want the male lead to be harassed by the female lead. Something like the trio bulling a boy in Great Teacher Onizuka only in the end the leader girl starts falling for him. Could involve blackmail, threatening or simply sadistic female lead.
Note - at the end they should end together or at least to hint being a couple.

Don`t mind josei, shounen or whatever. Please keep echi and harem titles well away and NO YAOI - I want heterosexual relationship.

Really? Nothing?
While waiting for suggestions I tried looking by myself. If someone is interested:
Satanic Sweet
Koi wa Tenka no Mawarimono
Kawaii Ore-sama

Too bad that`s all I got

Maybe Karakai Jouzu no Takagi-san? Though I'm not sure if you will mind the episodic nature or not

I`ll try it
thanks

Take a look at the following titles:

Kanojo wa Sore o Gaman Dekinai (IWASHITA Shigeyuki)
The female lead doesn't really bully the male lead, but she's sufficiently aggressive in her advances to make him distressed.

Henshin Ganbo by NisiOisin/ MIYOKAWA Masaru
This one-shot should be right up your alley. Short and charming.

IGARASHI Ran's Hoozuki-san Chi no Aneki
A 4-koma about a high-school student who gets horribly teased and bullied by his older stepsister for his sister complex. The series may be ecchi but not in the traditional sense for the sister is the one who knows her female assets and uses them to trip her brother up. As long as you stay away from the sequel, there shouldn't be a problem with the ecchi content.

Maybe you could try a genre search including tags like Female Dominance, Character Who Bullies the They Love or Teasing Protagonist


________________
"Stories are what death thinks he puts an end to.
He can't understand that they end in him, but they don't end with him."
- Ursula K. Le Guin, Gifts

To be savoured:
- Blood Alone by TAKANO Masayuki
- Otoyomegatari by MORI Kaoru
- Gangsta. by Kohske
- Seishun Kouryakuhon by AKIZUKI Sorata