Regular-sized, Purple Glitter Holofoil, Black-backed Coin featuring Mewtwo released as one of two coins available for earning 5 Play Points in events at the Japanese Challenge Road '99 held on June 10-11, 1999 in Osaka, July 18 in Fukuoka, July 23 in Hiroshima, July 26 in Sendai, July 30 in Nagoya, August 3-4 in Tokyo, and August 10 in Sapporo
There is an impression that it is difficult to obtain because it was distributed at events, but it seems that a considerable amount was distributed at multiple events, and people who know about the time do not seem to realize that it is a rare coin. Since it was distributed as a set of two coins along with another Exeggutor coin, the unopened item is in a bag containing two coins.