Lock On!

Lock On! is a shonen manga by Kenta Tsuchida. It's 18 chapters long plus the original one-shot.

The story follows Kurihara Niko, who Does Not Like Men, as she becomes friends with Sanada Utsuru, a Chivalrous Pervert who is a professional photographer at the age of 17. After transferring into Niko's class, Sanada decides to start a photography club with Niko's friend, Yuki. Sanada also has a special power called "Shutter Eye," which he can use to remember everything he sees perfectly.

Tropes used in Lock On! include:

All Men Are Perverts: Zig-zagged: Most of the guys who show up for a chapter or two end up sexually harassing someone, while Sanada is a Chivalrous Pervert, Yamato is only interested in Yuki, and everyone else is fine.
Berserk Button: Yamato is very protective of Yuki. Sanada doesn't like to see someone make a girl cry. When he ends up doing it himself, he jumps out a window...
Blessed with Suck: The day after Sanada uses his eye too much, he goes crazy.
Chivalrous Pervert: Sanada
The Ditz: Yuki
Does Not Like Men: Niko (This is changing)
Evil Eye/ Mismatched Eyes: Sanada's Shutter Eye is darker than his other one. He uses it to remember anything he sees perfectly and instantly.
Eyepatch of Power: Sanada uses one to cover his Shutter Eye.
Face of a Thug: Yamato and his father
Genki Girl: Matsuri whenever she takes off her glasses.
Hand Wave: In-universe: Sanada's explanation for all of his abilities is: "I'm a photographer."
Jerk with a Heart of Gold: Yamato and Ueno
Les Yay: There seems to be a lot between Niko and Yuki. It's because Niko Does Not Like Men and has a Limited Social Circle.
Living Lie Detector: Deconstructed with Sanada. His master tells him that his eye prevents him from understanding love.
Love Epiphany: Niko's last line: "...because even I was able to fall in love with you."
Love Triangle: Niko/Sanada/Matsuri
Meganekko: Matsuri
Older Than They Look: Machiko
Psychic Nosebleed: Sanada gets it when he uses his Shutter Eye. And whenever he takes pictures of girls.
Shipper on Deck: Invoked: When Sanada decides he needs to take more pictures of guys, he tries to get Yamato and Yuki together so he'll enjoy getting a picture of Yamato.
Shrinking Violet: Matsuri
Teacher-Student Romance: One of Ueno's students has a crush on him. But then he tells her he's not interested. It turns out he was lying, and he decides to wait until she graduates to do anything with her.
Tsundere: Niko and Yamato
Vitriolic Best Buds: Sanada and Yamato
What Is This Thing You Call Love?: Sanada