Friendship
A true friend is consistently willing to put your happiness before your friendship. It's said that "good advice grates on the ear," but a true friend won't refrain from telling you something you don't want to hear, something that may even risk fracturing the friendship, if hearing it lies in your best interest. A true friend will not lack the mercy to correct you when you're wrong. A true friend will confront you with your drinking problem as quickly as inform you about a malignant-looking skin lesion on your back that you can't see yourself.
A true friend inspires you to live up to your best potential, not to indulge your basest drives.
Of course, we may have friends who fit all these criteria and still don't quite feel kenzoku. There still seems to be an extra factor, an attraction similar to that which draws people together romantically, that cements friends together irrevocably, often immediately, for no reason either person can identify. But when you find these people, these kenzoku, they're like priceless gems. They're like finding home.
HOW TO ATTRACT TRUE FRIENDS
This one is easy, at least on paper: become a true friend yourself. One of my favorite quotations comes from Gandhi: "Be the change you wish to see in the world." Be the friend you want to have. We all tend to attract people into our lives whose character mirrors our own. You don't have to make yourself into what you think others would find attractive. No matter what your areas of interest, others share them somewhere. Simply make yourself a big target. Join social clubs organized around activities you enjoy. Leverage the Internet to find people of like mind. Take action.