lol.where.am.i

Yaoi and school life manhua. MC is an orphan but goes to high school even though he's 2 years older (20?) than his classmates. Works at a convenience store after school. Sits next to ML gray hair with a scar under his eye; 3 years older (21?) than MC. He smokes/drinks and has a family connected to a gang but he wants to go to school to pursue education.
Anyone?

Reincarnated FM long blonde hair. Was a female military sergeant in her past life but reincarnated as a duchess. Her family was known to have the best knights and now she's training them like a drill sergeant. There's a black hair ML who's the prince and the heroine is brown haired.