I forgot the title of this Yaoi they are ninjas and they have their own jobs and are quite wealthy now themselves but still serve lords and have pledged them since ancient times and one ninja who serves his lord is a young man who is constantly flirting/seducing him. I remember a scene where the lord told the ninja to reinforce the roof and he was confused but did it anyways and it turns out a rainstorm was coming and the lord was outside in the rain using a bullhorn to help citizens to shelters and stuff.

Please tell me the title!

Sorry not much help but try this list or search using "ninja" tag and yaoi option in advanced search.