I came across this eraser in the store today. It’s called a Jingu Miyamasugi (神宮御山杉) Plastic Eraser. On the front, it says that it uses wood from a sacred tree (shinboku 神木) that is over 300 years old and was taken from the grounds of one of Japan’s most revered religious sites.
While that may sound like a terrible fate for such an ancient tree (older than the U.S.), according to Mechtild Mertz’s Wood and Traditional Woodworking in Japan (2016), woodworkers generally don’t use this kind of timber except under special circumstances; indeed, the back of the box explains that the wood used here is from trees within the sacred precincts of the Ise Shrine complex (Ise Jingū 伊勢神宮) that have somehow been adversely affected by a typhoon or other similar event. That’s a relief. The eraser has its own web page that suggests you choose an eraser with a pattern that appeals to you (I did just that).
“Radar” is a plastic eraser produced by an Osaka-based company called “SEED” (Kabushikigaisha Shīdo 株式会社シード), which has been around for more than 100 years, originally founded as the Miki Kōsaku Rubber Manufacturing Plant (Miki Kōsaku Gomu Seizōsho 三木康作 ゴム製造所). Although the box clearly says that this eraser has been produced since 1968, according to their website, it was first developed in 1965. Perhaps 1968 is the official year, though, because they released a limited-edition 50th anniversary eraser this year.