Hello, I'm searching for a yaoi (or, at least, a shonen-ai) manga where the two lovers are both little boys, like from elementary school.

And if someone know the name of this manga: https://it.pinterest.com/pin/700028335800785563/ please tell me. Thanks.

The image looks like young Kagami and Kuroko from KnB. I'm not sure if it's a dj or just an illustration.
As for the recommendations, I'm not that versed in shota but here are a few I liked,
Somaru
Nora neko to rain days
Some authors whose works you might like(most if not all their works have elementary/ secondary school kids in them)
S size (Shinachiku)
Shikimura
Shigeru
Tsukumo Gou
Kawada Shogo
Hoshiai Hiro
Kugi
Eichi Jijou (Takamiya)