When they hit High School, Daisuke's friends (the ones who aren't Digidestined) always wonder what he even has in common with Ichijouji Ken. Because they don't hang out like normal boys their age do- in groups, at movie theaters, at school. Daisuke has, what they call, his "Designated Ken Days" and it's baffling, really, because Ken doesn't like video games or loud music or cheesy anime or any of the gaudy, extreme things Daisuke does.
He plays soccer, but not as much as he used to when he was younger.
"So what do you even do?" Ken is oh so very polite- Daisuke always introduces him: "This is my best friend, Ken."- but very quiet. His hair is long and his manners are impeccable and he sort of draws up his shoulders and brushes his bangs behind his ears and makes casual conversation but he still strikes you as a socially awkward person who has no idea how to talk to someone about trivial, everyday things like pop culture or the weather.
So here's Motomiya Daisuke and he's loud and ungraceful and likes the kind of things which boys like that make girls roll their eyes. And here's Ichijouji Ken who's shy and refined and thoughtful and who isn't quite a genius anymore but still enjoys things like literature, philosophy and silence.
What they have in common is this:
Ken lets Daisuke talk. It's not so much letting as listening. Daisuke rambles and rants and raves and makes really bad jokes and oftentimes is a voracious practitioner of "I just don't know when to shut up" and usually he makes an idiot out of himself. Ken listens to every word that Daisuke says not patiently but patently because Daisuke is full of life and ideas and there's a spark in his spirit, in his eyes and in his words that Ken doesn't think he'll ever get sick of.
Daisuke never thinks of reading anything that isn't manga unless Ken shoves a book into his hands, smiles wryly and says: "Well, you'd like this one." and sometimes Daisuke opens up to the first page just so he can make fun of the opening paragraph and finds himself awake at three in the morning still reading by computerlight with Ken fast asleep, slumped against his shoulder and V-Mon asking, every three minutes, what's happening now, Daisuke?
And mostly because Daisuke knows when not to talk and Ken knows when not to act superior and they can just sit there in perfect, comfortable quiet, side by side watching the clouds, the sunset, the traffic, the people playing in the park and they can be thinking two completely different things yet, somehow, they exist in the same world until Daisuke says: "hey, Ken, doesn't that cloud totally look like a turtle eating a rhinocerus?" or Ken says, "it's suppertime, mom'll be expecting me" (and Daisuke asks: "hey, is she making chicken curry tonight?")
They've shared blood and tears and fire and heartbeats. Daisuke doesn't want to get all mushy about it, but there isn't anything he wouldn't do for Ken Ichijouji.
Daisuke can't really explain any of that, so instead he says: "We don't need to have anything in common. He's my best friend."