MaeIso

MaeIso is the slash ship between Hiroto Maehara and Yūma Isogai from the Assassination Classroom fandom.

Canon
Maehara and Isogai are canonically childhood friends and neighbors. Their friendship dated years before the start of Assassination Classroom, making them the oldest-friendship in the Class of 3-E.

When Maehara gets kneed in the stomach by Takaoka for speaking up against him, Isogai looks worried and is the first to help Maehara. They are later seen together again while Maehara recovers.

They are still friends after graduation, appearing even friendlier than they were in school.

They are seen a festival together along with Chiba and Hayami.

On the official cover of the anime opening song, "Bye Bye Yesterday" Maehara and Isogai are in the background. The flowers petals around them resemble hearts.

Moments

 * Maehara and Isogai arrive to school together.
 * Training together.

Fanon
They are a popular ship likely due to their aesthetic and strong friendship. People also started shipping them when Maehara is talking about how great Isogai is at the cafe the latter works at and in one of the flashbacks, Isogai is holding up a plate of the goldfish to cooked; some fans speculate that the memory is from Maehara's perspective and therefore, Isogai is feeding Maehara.

Maehara and Isogai like each other but don't realize it.

Their friendship was platonic at the beginning but turns romantic after "insert event."

It is the most written ship for Maehara and Isogai on AO3.

Fandom
FAN FICTION 

TUMBLR

Trivia

 * Maehara and Isogai are two of the three mentioned by the girls of 3-E as "good-looking/handsome".
 * Isogai and Maehara are the top knife-users in their class, this is notable parallel to a semi-canon ship, ChiHaya, which refers to the ship between the class's top sharpshooters.