I am watching a current anime, That Time I Got Reincarnated as a Slime ( 転生したらスライムだった件 ). The protagonist, now a reincarnated slime in the isekai story, is making friends with a dragon. The specific conversation begins at time code 20:30 of chapter 1*. After they have agreed to be friends, he thinks to himself (sub, time code 21:17):
It's a little embarrassing talking about "friends" at my age...
He was 37 when murdered. Why would he be embarrassed to use the word "friends"? Is there a better word to be used between adults?
* Link is to Crunchyroll, an American streaming service. I don't know what other countries will be able to view it.
This question is a follow-up to What is Japanese version of the pun word, “slife”? … and term for adult friend?. On Anime & Manga SE. @кяαzєя answered it, and he suggested I post a follow-up question here.