According to information for the Greninja obtained at the beginning of the game's pre-release demo, the name of its original trainer is 'Ash'. This Greninja also met Ash on October 17, 2013, the exact date the first episode of the Pokemon XY Anime was broadcast in Japan. In the episode, Ash Ketchum met Greninja as Froakie.

After the killing of Harambe in the Cincinnati Zoo, many upset fans wanted Harambe to be added to the Pokedex in Pokémon Sun and Moon. Fans created a change.org petition outlining their wish, and the petition went on to gain over 120,000 signatures. Despite the amount of support, there has been no official comment from anyone affiliated with the Pokemon brand.

Marowak's Alolan form with its new Ghost typing is most likely a reference to the non-playable ghost of Marowak found in Lavender Town's Pokemon Tower all the way back in Pokemon Red, Blue, Green, Yellow, Fire Red and Leaf Green.

Raichu's Alolan form is a reference to the Surfing Pikachu seen in many Pokemon releases ranging from games to merchandise. More Specifically, Alolan Raichu seems to be based on surfing Raichus from Pokemon Stadium. This Raichu is surfing on its tail and even has the ability "Surge Surfer" and the special Z-Move "Stoked Sparksurfer".

Z-Moves were introduced in order to have something that would allow players to use a wider variety of Pokemon in battle.
Rather than have an individual Pokemon that players can focus on and make strong like with Mega Evolutions in Pokemon X & Y, Z-Moves were designed as a system where any Pokemon can use them and be stronger and more relevant in battle.

To help commemorate the 20th anniversary of the Pokemon series, the developers wanted to look at trainers and Pokemon as living things and express that in a better way. When coming up with ideas for Pokemon Sun & Moon, they created a theme for the game based around the concept of life, with both the sun & moon both being important to all life on earth. A place that came to mind to reflect this was Hawaii, an area with lots of sunshine, clear nights, and an abundance of life.

Ash-Greninja was added to the games to encourage fans of the Pokemon anime series and especially kids to try out the special demo version (which Ash-Greninja appears in a special Pokemon that is able to be transferred to the full game), as it was a popular character among them.

The time difference between the versions was inspired by the idea that Pokemon are living creatures - some are active during the day, others are active during the night. The developers thought this would be a useful feature to facilitate more communication and trading amongst friends.

Pokemon Sun & Moon was Shigeru Ohmori's first time as the director of a new generation of Pokemon games. Because the game commemorates the 20th Anniversary of Pokemon, he wanted to go back and look at what he thought Pokemon games should be and create his own take on the series. He came up with the idea of Trials & Totem Pokemon as a replacement for Pokemon gyms to tie in with the Alola region's theme of powerful and abundant nature. He thought it would be an interesting concept and a way to make the game feel fresh for both veterans of the series and newcomers alike.

Alolan forms were introduced by the developers in order to illustrate that Pokemon are living, changing creatures. Pokemon who had migrated to the Alola region would therefore follow a different evolutionary path than their original counterparts, similar to the way real animal species in the Galapagos Islands followed their own unique evolutionary paths.

In order to create these Alolan forms, the developers revisited the Pokemon that originally appeared in Pokemon Red & Blue, since they are widely recognized by long time fans and would best express this concept with them. It would also help commemorate the 20th anniversary of the Pokemon series as a special surprise for fans.

It is possible Exeggutor actually hails from the Alolan islands, as its Pokedex entry in Ruby, Sapphire, Emerald and their remakes states that it originates from the tropics. Alola is the first tropical setting in the series and features its own version of the creature. Furthermore, Exeggutor's Pokemon Crystal Pokedex entry states that in a good environment it will grow more heads, as is seen on its Alolan form's extra branch.

Sophocles's shirt has an image that resembles a Game Boy with link cable which was how Pokemon used to be traded in earlier installments of the series before wireless communications existed.

In the Pokedex, it's stated that Yungoos and its evolved form Gumshoos aren't native to the Alola region but imported from another country. It's implied that they were brought to Alola to get the Rattata and Raticate population under control but they rarely see each other because Yungoos and Gumshoos are diurnal while Rattata and Raticate are nocturnal.

This is a reference to when the state of Hawaii had a problem with Polynesian rats eating up sugar cane crops in the 1800s. They imported Small Asian Mongooses to kill the rats. However, while the rats were able to adapt to being strictly nocturnal, the mongooses stayed strictly diurnal. Because of this, both species have become a major problem in Hawaii.

If you go into your Poke Finder and take a picture of a large body of water, there's a chance you'll get a comment that says: "7.8/10 Too Much Water." This is very likely a slam at IGN's review of Pokémon Omega Ruby & Alpha Sapphire for criticizing the later half of that game for having to use water-based HMs like Surf a lot.

Between 2016 and 2017, male specimens of a new species of Nocticola cockroach were discovered at the Bukit Timah Nature Reserve in Singapore. The species' discovery was first published in 2023, and it was also announced that it had been named after the Ultra Beast Pheromosa, a Pokémon designed to resemble a "freshly-moulted" American cockroach, from the Generation VII games Pokémon Sun & Moon. The authors of the findings were fans of the series and noticed similarities between the two, including "having a long antenna, wings that mimic a hood and long slender legs." Unlike the hardy American cockroach, cockroaches in the Nocticola genus are very delicate and are known to be found in Africa, south-east Asia, and Australia. This species, Nocticola pheromosa, is the first scientifically-documented instance of a Nocticola cockroach in Singapore.