Sorry
You'll barely see Tatsuha (he's Yuki's younger brother) but reading the manga made him my favourite character
The "badass writer" (aka Yuki), is so angsty and difficult ... If you had to read one volume of the manga, I'd say pick six
It's the "YOU BETTER TAKE YOUR BOYFRIEND ON A DATE OR ELSE!" volume
Mirage isn't that well known. It was released a few years ago state-side, but it confuses a lot of people. It's based on a 40 volume novel series, with the 13-episode series covering the first five novels, I believe, and the OVA covering novel 10. Basically, a ton of samurai warlords are all reincarnated and continue this battle from 400 years ago, and it's the job of the Uesugi to send their souls to rest. The story picks up with a boy named Takaya, who is about to find out he's the reincarnation of Kagetora, the leader of the Uesugi. Because of vaguely explained events something that happened 30 years ago with his lover Naoe, Kagetora has forced himself to forget everything that's happened in the past 400 years.
Naoe shows up, confuses the hell out of poor Takaya/Kagetora, and angst abounds while they run around battling evil spirits
I personally like the OVA better (the art, music and story are better and Kagetora has regained enough memory to bite back) but it won't make sense if you haven't watched the series. I consumed all of Mirage last week myself, and it has eaten my very soul.
If you're looking for anything related to shounen ai/yaoi,
aarin fantasy is the only thing you need