Daikaya is owned by the same restaurant group as Haikan. The menus and concepts are different though. The ramen bases at both spots are different as are the noodles.

I used to work for the company and because of that am definitely biased but even if they don’t offer some of the most popular styles of ramen (because they don’t match the concepts) their noodles are top tier. Each restaurant has a specific spec that is produced specifically for them by Nishiyama. If I’m getting ramen in DC it’s at one of the Daikaya spots (haikan, bantam king, Hatoba) or Menya Hosaki