Kaii-san and I

"Even though Kaii-san can see us humans, there are only a few people whose voices can reach him, right? So I think it's a bit lonely if those who can see him don't get to know him." A boy looking for friends and some clumsy Kaii. The strange and mysterious friendship-making begins!

(Source: Kadokawa, translated)

Note: Originally self-published on Twitter, was then licensed by Kadokawa for commercial release.