If you have a chance to buy a ballpoint pen in Japan, I strongly recommend JETSTREAM, which is a brand of an oil-based ballpoint pen. It enables you to get super smooth writing. You can buy it everywhere, convenience stores, supermarkets, ¥100store such as DAISO, not only stationery stores. And also the price is cheap. ¥115~per peace.
JETSTREAM is not only one type. There are several kinds of products. I like the rubber holder type, which is the right one in the picture above. ¥252 (As of Nov. 2022). I like the feeling of a hand gripped of it.
By the way, are you familiar with “oil-based ballpoint pen”? I found the right description about it on the MITSUBISHI PENCIL official page, which is the company of JETSTREAM.
You can see all kinds of JETSTREAM on this official page(English)
On the Japanese page of the same site, you can see all types of JETSTREAM.
With JETSTREAM, I feel like I can write good poetry…