Seiryuu no Kenshin: Anata ni Sasageru 300-nen

Kohaku, outcast of the White Tiger Clan, once shared an unbreakable bond with Seiryuu, chieftain of the Dragon Clan and lord of the beastfolk. As children, Seiryuu was the only one who made Kohaku feel like he belonged. But the centuries have driven them apart—Seiryuu now hides behind the facade of a constant smile, and Kohaku can no longer trust his heart to the whims of another. On the rare occasions that the two met, Seiryuu would casually propose marriage, only for Kohaku to refuse, unwilling to believe in his cavalier promises. However, things change when Kohaku finds himself next in Seiryuu's long line of matchmaking partners. Despite everything, nothing could have prepared Kohaku for the secret Seiryuu has been hiding for all these years. As the truth begins to unravel, can Kohaku finally understand his old friend's feelings? Or have time and trauma already doomed their chance at happiness?

(Source: J-Novel Club)