There is plenty of Nintendo's history that is well established, especially the more recent period of its video game business. Of course, the company goes much further back with an assortment of previous business ventures, with the original and most famous being Hanafuda and playing cards. It would eventually establish itself as a leader in that field in Japan, but some interesting research suggests that the very early history of the company may be due some revision.
In an article posted by Marcus Richert on Tech Radar, they explore Nintendo's founding year of 1889, which is the most commonly agreed period of Fusajiro Yamauchi creating the company. Their research suggests that the company was actually formed in 1892, three years later, and it seems there's documentary evidence to back that up. Reichert found historical records that consistently show 1892 as the founding year of the company, with the earlier date only emerging in records and popular perception decades later:
In business directories from the Taisho and early Showa periods such as the Teikoku Shinyo-roku, the company's founding date is consistently given as 1892, some three years later than Nintendo's claim.
I've dug through hundreds of documents in Japan's National Diet Library, and the earliest mention of the 1889 date I found was a listing in the 1936 edition of the Teikoku Shinyo-roku for Sekiryo Yamauchi, Fusajiro's son-in-law/adopted son and the second head of Nintendo.
...Now, it’s not inconceivable that Sekiryo realized, perhaps through the unexpected unearthing of some old document or in a conversation with his now 68-year-old father-in-law, that Fusajiro had founded the company when he was 21 rather than 24. It seems more likely that Sekiryo simply misremembered the date when the editors of the directory reached out to him to double-check it, and then it stuck.
The article also goes on to address a photograph often cited as showing Nintendo's first headquarters in 1889, with historians nevertheless suggesting that a bicycle in the shot actually dates the image between 1912 and 1930.
Further on in the piece Richert analyses some Edo-period cards from earlier in the 19th Century, suggesting that two examples bear references to Fusajiro Yamauchi's birth father, Sosuke Fukui. It's suggested that this may show an earlier influence that pre-dates Nintendo's business. A form of the logo present on these older cards is still used in Nintendo's cards to this day.
The latter theory is less conclusive, ultimately, but it does seem clear that Nintendo may have been founded in 1892, rather than 1889. It'll be interesting to see if Nintendo addresses or revises this detail, perhaps when it launches its 'Nintendo Gallery' space in the next couple of years.