[UPDATE 04/14/22] This post has been rewritten after I had time to sort out the details
A recent 3DS eShop update in Japan has called out two of Bandai NAMCO’s licensed titles that will be removed from sale on April 18th at 10:00 JST (April 17, 9pm EST). Sentouchu: Densetsu no Shinobi to Survival Battle! and Chou Sentou-chuu Kyuukyoku no Shinobu to Battle Player Choujou Kessen! are both based on the ‘Battle for Money’ television game show which was a spin-off of the original program ‘Run for Money (逃走中)’.
For the next few days you can still pick up Sentouchu and Chou Sentou-chuu from the 3DS eShop in Japan. Both titles were released to retail in Japan so at least they won’t be completely lost after the deadline. Thanks to @StarlacUK for pointing out the news. I’ve added the date to the Watch List calendar and will have pages up on the site later.