Six books in the Kosuke Kindaichi series by Seishi Yokomizo are on sale right now in the US and the UK. These mysteries are so classic in Japan that Yokomizo has a Japanese mystery book prize named after him, which per Wikipedia, includes “a statuette of Kosuke Kindaichi and a cash award of ¥10,000,000, making it one of the richest literary prizes in the world”.
In the last few years, several of Yokomizo’s mysteries have been translated into English and published by Pushkin Vertigo. I’ve had review copies of two of these, and liked them both – see here and here. Now, the first six translations are on sale for $1.99/£0.99 in the US/UK, and they are also discountable at Kobo UK. The translated titles that are on sale are: The Honjin Murders, The Inugami Clan (apa The Inugami Curse), The Village of Eight Graves, The Devil’s Flute Murders, Death on Gokumon Island, and The Little Sparrow Murders.
And here are price-sorted links (please note that the links include a few strays) to all six at Kindle US | Kobo US | Kindle UK | Kobo UK