The Guan Nan Big Mart is hands down my favorite stationery store so far in Taipei, Taiwan. Although they sell more than just stationery, and there are 3 floors.
The Zebra Mildliner is probably one of the must have items for bullet journaling or note-taking. I’ve been using them for a year now, and I found out about them from bullet journaling community. But they are really great for notes and drawing as well.