Hi, i am looking for some manga/anime with mc who have some kind of obsession, for example there was o guy who was obsessed with rocks and girl obssesed with animals or it can be something like bad direction or anything similar. Something what kind of irritates his/hers friends. I am ok with any genres, but i would prefer shounen series, but as i said everything is ok. Thank you for every concern and sorry for my english ^^

You should try browsing some of the categories, such as "Obsession" and "Fetishes."

As for my recs:
Cuticle Tantei Inaba - Hair fetish, which is more humorous than serious, but still an important plot point.

If people count, then Boku wa Mari no Naka, for a guy who obsesses over a "perfect" girl. Ditto for Tomie, though the latter is an absurdist horror and the former a serious psychological story.

Mofu Danshi - Cute things. A really funny story.

Fetish, as the title implies.

Enami-kun wa Ikiru no ga tsurai - mc is obsessed with a 'novel-like encounter'.

Ore no Himekutsu o Haite Kure is about a shoemaker with an unwanted foot fetish. I can also second the recommendation for Boku wa Mari no Naka, a great manga! Both are seinen. Ai Kora is a shounen about a boy obessed with various parts that make up a perfect girl. I haven't read it, but it is generally well liked.

Why did men stop wearing high heels? about a guy obsessed with heels (not yaoi, if that turns you off)
Kanojo wa Sore o Gaman Dekinai a beautiful assistant teacher is obsessed with the smell coming from a loser in class that wears a dog costume everywhere

Holyland where the main character becomes obsessed with throwing punches and then fighting
Sukimasuki where the MC is obsessed by gaps and small spaces
Sekine-kun no Koi here it's knitting but I guess it acts more like a coping mechanism than an active obsession...
Self that is about masturbation

In Kuragehime, all the main characters have some sort of obsession. (trains, older men, history, jellyfish, crossdressing, dolls, etc.)