cairnsy uploaded three SaiMono doujinshi, which are, in no particular order:
1. Ryuuki is a puppy and everybody cuddles him and I think once he tries to avoid deciding who he likes best of Shuurei and Seiran by saying he likes white rice and then Seiran, as an evil big brother must, tells Shuurei this, and they are both heartbroken at the discovery that Shuurei likes white rice best too. Basically it attempts to ship everybody at least once and mostly succeeds. The quality wasn't very high on the scans so I'm not sure of the reading.
2. Shuuei and Kouyuu antics as shinshi. With Reishin being himself.
3. "Kouyuu had dignity, but then he started sleeping with Shuuei."
Dammit now I want a couple of these for myself! .....I don't suppose...?
Also someone needs to write the one where the Shi brothers are like WE'LL PROTECT U at Shuurei during a thunderstorm and they coo a lot at her and cuddle her and after she falls asleep Seiran pets Ryuuki's hair. Also also the one where Ryuuki basically camps out on Shuurei's lap for hours and gets his hair brushed and is eventually discovered in a boneless pile of happy purring on Shuurei by his honored sibling, who then tickles the unholy hell out of him.