Both of these Japanese omnibus films use songs as the inspiration and central message/motif/theme for each short film contained within.

Both of these stories present a premise in a similar vein of "Mr. and Mrs. Smith": That of a married couple who are unwittingly from rival factions of killers/assassins/etc. Both are full of comedy, hijinks, action, and a healthy dose of rediscovered romance.

Both of these incredibly fluffy BL dramas center around one of the leads being a closet simp for the slightly crazy (and slightly dumb) energetic lead. They also feature hilarious imagination sequences, a super supportive best friend that steals the spotlight, and a high school setting.

These two horror mystery dramas center around a male protagonist and his special eye that provides him with abilities/knowledge that others do not.

These 2 BLs are very different in tone, but do share a few key similarities:
Both of these stories take place in the upper grades of high school and have a significant subplot that critiques the education system as not benefiting all of its students.

The leads also have a rather similar dynamic of a flirtatious enemies-to-lovers-esque dynamic between a shy top student and a shameless classmate determined to make his mark. Both couples excel at chemistry that comes from their gazes to each other.

Both of these love stories revolve around protagonists going through time in different directions (i.e. one person moving forward, another moving back - resulting in one's first day together being the other's last day). They're both highly emotional stories as a result of this seemingly ill-fated love.

Both of these BL dramas revolve around 2 boys getting involved with each other through a fake relationship in which one party has had a long-standing secret crush on the other, and the other struggles with his newfound sexuality and fluctuates between petty and friendly behavior. They then enter into a semi-secret relationship only known by their supportive/energetic family and friends.

Also, both being GMMTV BLs, these two dramas share several cast members - including the main couple pairing of My Tee being the second couple pairing in 2gether.

The main couple in 'Cause You're My Boy/My Tee reminds of the Pond and Cha'aim couple from Love By Chance. A crass hyper-sexual porn-obsessed young man with a love-interest who is significantly less interested in sex. Both couples have a rocky back-and-forth going on before eventually settling into a romance.

Both BL stories feature around two classmates whose relationship frequently fluctuates between being friends, enemies, and, eventually, lovers. They frequently stay over at each other's places under the guise/excuse of studying. And the dad of one of the leads in each knows more about their secret relationship than he lets on.

While very different in premise, both of these dramas center around one of the characters having to leave and, after coming back, finding their friend-group as supportive as ever and ready to pick up where they left off.

Both of these dramas are friends-to-lovers BL dramas that really pull at your heart strings. And after seeing one of the leads pining in his currently-unrequited love, later on we get to see the tables turn and the other lead feeling all of the emotions that he un/intentionally made the other one feel.

Both of these BLs revolve around two students (classmates in "His, Cat", and student/tutor in "You Had Me At Hello") who discover feelings for each other while studying together. This newfound dynamic catches the attention of concerned relatives who plead for their separation.