A Gift to the People You Hate has a principal theme of hate and revenge. This theme is reinforced by the gift shop whose owner is offering gifts of different levels to those who wish ill to the person they hate - the most extreme of which is death. This mechanism of wishing death is also reflected in Death Note by writing the name of the person in the notebook. Both also have a character that is a "girl idol".
A Gift to the People You Hate has a principal theme of hate and revenge. This theme is reinforced by the gift shop whose owner is offering gifts of different levels to those who wish ill to the person they hate - the most extreme of which is death. This mechanism of wishing death is also reflected in Death Note.
Gameboys is similar to Theory of Love because of the BL theme. Also, both series are primarily focused on the two main characters who at the onset do not have reciprocated feelings towards each other but later on they will.
Just like 2gether, Kiss Me Again also featured BL relationship in one of its main characters. Although both of the shows had the same Director (Champ), I think Kiss Me Again was done better compared to 2Gether.
2 Moons and My Engineer fall under the theme Boys Love. The setting of both titles are also in a university. There are characters in both shows which have same characters (e.g. innocent, confused, etc.). Casting in the two shows are also good.