Hi!
I've been searching through the forums for manga with lots of friendship and character development, however, none of the posts I've looked through satisfied me.

I want manga revolving around a group of friends (3+ people), not just between two best friends. My favorite part of group friendship is when the story goes into the background and life of each friend. Anything is fine except shounen ai, shoujo ai, yaoi, yuri, ecchi, sports, and harem. Also it actually doesn't matter to me if there's romance or not. If there are any posts with similar requests as mine please guide me there!

On top of my head I prefer manga//webtoons like
Nijiiro Days (MIZUNO Minami)
Girl's World

but I also really liked the friendship groups in:
Noblesse (Rai, Frankie, and the RK squad, also the group of kids )
Kono Oto Tomare! (The Koto Club)
Cheese in the Trap (Euntaek, Bora, and Seol)
One Piece (Strawhats)

Thanks for your time 😀

Definitely Angel Densetsu. The group of friends is a little slow to form up, but if you like friendship I can definitely recommend it.

how about Koi wo Shiranai Bokutachi wa and maybe even Lookism or Tower of God ?

horimiya

Hachimitsu to Clover
Suki tte Ii na yo.
Cat Street

tetsugaku letra

Apologies in advance if my suggestions are not quite meeting your request.

7 Seeds Aside from the old-school shoujo art, this has been my favourite when concerning characters' growth and development. There are multiple groups, with each group being focused on and showcasing the various characters, their background and relationships.

Akatsuki no Yona Yona along with Hak and the four dragons are a fearsome, yet lovable bunch.

Iris Zero An outcast is brought into the female lead's social circle, which slowly strips away his loner status. Each friend has their own particular event/relation with the male lead, where their character as a whole are explored.

Kaguya-sama wa Kokurasetai - Tensai-tachi no Renai Zunousen The student council is a rag-tag group of eccentrics, but their friendship holds strong despite their differences.

Dadadadan. The summary is self-explanatory. Though character development may be a little lacking as it is mostly a comedy, it still goes through the trio's background, and their bromance never falters.

ReLIFE A heartwarming and heartbreaking story. Though he was reluctant at first, the main character's year spent as a high school student and his group of friends helped him break free from past traumas and create friendships he'd always remember.

Orange (TAKANO Ichigo) A bit of a tearjerker, but worth checking out. The female lead surrounds herself with amazing friends, who all attempt to save a transfer student suffering from depression.

Kareshi Kanojo no Jijou
Yumemiru Taiyou

And I 2nd all of hkanz as well as Orange