There are some kinds of Obi for Kimono, and “Fukuro-Obi” (Double-woven obi) is used for formal occasion. “Nagoya Obi” is easy use for everyday casual Kimono, and it’s easier to tie than Fukuro Obi. It’s convenient because it can be used for kind of serious situations.
Kimono and Obi are enjoyable to match, you can get your own unique one when you pick color and the design. If you remember “for a formal Kimono wear a formal Obi, for a casual kimono wear a casual obi”, you can just enjoy various styles with your own coordination. There are a lot of women who express personality on the Obi-dome and enjoy Kimono.