Incest

Brother x brother (no blood relation)

Ch.1-3, 5.5 Love is Close - His lil adopted bro (already taller, handsome & popular) loves him to the point of stealing his undies & even putting them on his head. Σ( ￣□￣||) As a big bro (chibi), he'll get him on the right path. - We all know he'll definitely fail.

Uncle × nephew (one shot)

Contains a little incest between cousins

Brother x brother (no blood relation)

«✤[]✤» Story of 2 stray orphan bros; The mysterious plot is great. I would like it more if the mangaka let us see them met and see those two pairs love scenes. [Spoiler] ...
✤ Ch.1, Ch.2 Pg.55 Seven - Mitsuha, a writer's searching for his lil bro, Nanao whom separated since he's 3. Meanswhile the previous store owner picked up an amnesia 12 yrs old boy & name him Nana which means 'no name' or 'seven. Are Nana & Nanao the same person?
✤ Ch.2

story 1 (p. 3-94 + 131-159) cousins
story 2 (p.95-130) teacher x teacher