Well, I was objected to by a close friend.
Koichi and Viet are good friends. They are more than friends, but not lovers.
"Hey, you know what? Sara is going out with Beth." "What? I didn’t know that. I thought she was my best friend but she never told me about that."
A friend who is like one of your parents is someone who will look out for you. They are like family, in fact! That's why this word means best friend or close friend. Just imagine someone who watches over you like a parent would. This is the way to describe them.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.