I just want to live, is that so wrong?

Both outfits are based on kuromontsuki haori hakama and kurotomesode (both outfits of the highest formality for married men and women, respectively). I'd like to think they commissioned a matching set to wear as a couple but March took a special liking to the haori and put his own spin on it!

The symbol on the outfits are their family crest after marriage, which combines the symbol on March's necklace (my interpretation of it is of a stylized anvil) with a white circle representing a full moon and a cherry blossom for Cheri's side.

Neither of them wear rings. For March it's because wearing a ring would bother his work (but he still made a plain silver band to put on his new necklace), for Cheri it's because she has her sword and tanto (dagger tucked in her belt) instead to indicate her marriage status. Both are made by March!

It's part of my greater worldbuilding for Cheri's story, but the gist of it was that symbolic items like rings hold no value in the marriage traditions of her homeland; people give their spouse-to-be a betrothal/wedding gift that they can use in their day-to-day life instead. However, as a consequence of the wartime era, this gift ends up taking the form of weapons, most commonly swords. And due to the amount of time, effort, and degree of personalization that can go into forging a sword, gifting someone a sword becomes associated with marriage specifically, i.e. an auspicious and lavish occasion merits an equally lavish gift.