@shukudaidayo.eth
As a big fan of the Yamato schools, it's a real pleasure to see a Hosho school sword like this
The surface of most swords has a "wood grain" pattern, but the Yamato schools are known for their masame, or long, continuous lines that flow along the length of the sword.
Probably not great structurally-speaking, since there's a risk of delamination, but definitely a striking appearance!
https://www.aoijapan.com/katanamumei-attributed-to-den-hosho-nbthk-tokubetsu-hozon-token/