[Well, it's a bit like getting The Talk from a sex offender. This probably isn't how someone more normal would explain it to you, it's just the most obvious way he can think of.

Although there's also ... he looks like he's taking something from thin air and twisting it between his fingers, but then it resolves into a jet-black thread coming out of his chest and stretching out into the distance. It catches the sun as it moves, glittering darkly. It's only a little thinner than the cord on Nisei's headphones, but it stands out as starkly as the name written on his other hand. Bonds saturated with love are ethereal; luminous and weightless, tracing impossible curves in the air. A chain like the one connecting him to Seimei looks like someone managed to condense enough steel to hold up a bridge into piano wire. It's as distinct as any other physical object, despite the gossamer shimmer of magic.]

No one starts out being able to see bonds. [He says softly. And as soon as he lets go of his, it fades into invisibility again.]