The dramas with a bromance theme I have seen is school 2013, Shut up flower boy band, Sungkyunkwan scandal, I Am sorry I Love you, I remember you, Rooftop prince, Flower boy next door, She was pretty, Kill me Heal me, Sassy go go, reply 1997.
Aozora no Tamago
Ho Goo's Love
Bromance
Mr. Back
A Different Kind of Pretty Man
Share House no Koibito
Pin to Kona
Smile, You
Warrior Baek Dong Soo
it's just starting but.... Descendants of the Sun
Sassy Go Go has a really strong bromance in it, and so cute! Also has romance too though, so I don't know if that's what you'd be interested in.
Others are
Bromance
School 2013
I Remember You
Shut Up Flower Boy Band (one of my absolute faves!)
Reply 1997
Ojakgyo Brothers
Brother Beat

Both are family dramas, each with a set of 4 brothers who go through all kinds of hilarious trials & tribulations together. I really enjoyed both.
Off the top of my head (all are J-dramas unless otherwise noted):

Battery
*Beach Boys
*Ikebukuro West Gate Park (though it gets dark at times and since OP doesn't like violence/fighting, probably not for them)
*pretty much any Kamen Rider series (some *cough*W*cough* border on straight-up romance rather than "bromance")
*Kisarazu Cat's Eye
*Mahoro Ekimae Bangaichi
Nobuta wo Produce
(though I see the OP has already seen this one)
*Ping Pong (J-movie)
Samurai Sensei
*Stand Up!!
*Tiger & Dragon
Tumbling
*Water Boys
Youkai Ningen Bem

(though I like all these-- I wouldn't recommend them otherwise-- the * means it's an especially-loved title)
Orthros no Inu - for tortured bromance
Fuben na Benriya - for comedy
ST Aka to Shiro no Sousa File - good for shipping too
(J-dramas)
Fuben na Benriya
Tiger & Dragon
Tokubou 
First of all, I love this Post <3

Bromance 

School 2013 (I hope one day there will be a bromance Drama like School 2013 <3)
Secretly, Greatly
I Remember you
My friend is still alive
Sassy Go Go

Boys Love

Seven days
Like Love
Love Sick
Two Weddings and a Funeral
For Love, we can
A Gentleman's Dignity - it's a must watch for bromance lover :) beside the romance between the male lead and the leading lady it's all about friendship of 4 men, watching those four in action made me cry from laughing...

The Bridal Mask - very complicated relationship between two friends and those two had more chemistry than the "main couple"

Bad Guys - it's about the most dangerous criminals who are after other criminals, the relationship between those three "bad guys" is very interesting and it develops well during the show
Nirvana in Fire (this drama is super long but its really good and the focus of this drama was legit the bromance, the romance line was weak)

watch these 3 FOR SURE it's about bromance between invloving real brothers/siblings <3

East of Eden

Wakamonotachi

Brotherhood of war