- Pokémon Red and Green (1996) - Parametric Design, Map Design
- Pokémon Blue (1996) - Parametric Design, Map Design
- Bushi Seiryūden: Futari no Yūsha (1997) - Map Design & Balance Check
- Pokémon Stadium (Japanese) (1998) - Advisor
- Pokémon Yellow (1998) - Game Design, Parametric Design, Map Design
- Pokémon Stadium (1999) - Advisor
- Pokémon Gold and Silver (1999) - Game Design, Parametric Design, Map Design
- Pokémon Crystal (2000) - Game Design, Game Scenario, Parametric Design, Map Design
- Pokémon Stadium 2 (2000) - Advisor
- Super Smash Bros. Melee (2001) - Original Game Staff (Planning: Pokémon)
- Pokémon Ruby and Sapphire (2002) - Game Designer, Plot Scenario, Map Designer, Parametric Designer
- Pokémon Colosseum (2003) - Pokémon Advisor
- Pokémon FireRed and LeafGreen (2004) - Planning Leader, Game Designer, Parametric Designer
- Pokémon Emerald (2004) - Game Designer, Scenario Plot, Parametric Designer
- Pokémon XD: Gale of Darkness (2005) - Pokémon Advisor
- Pokémon Diamond and Pearl (2006) - Game Designer, Plot Scenario, Map Designer, Parametric Designer
- Pokémon Battle Revolution (2006) - Pokémon Advisor
- Pokémon Platinum (2008) - Game Design, Plot Scenario, Map Design, Parametric Design
- Pokémon HeartGold and SoulSilver (2009) - Game Design, Parametric Design
- Pokémon Black and White (2010) - Battle System Design, Pokémon & Trainer Parameter Design
- Pokémon Black 2 and White 2 (2012) - Game Design, Map Design, Parameter Design
- Pokémon X and Y (2013) - Game Battle System Design
- Pokémon Omega Ruby and Alpha Sapphire (2014) - Game Battle & Contest System Design
- Pokémon Sun and Moon (2016) - Battle Planning
- Pokémon Ultra Sun and Ultra Moon (2017) - Battle Planning
- Pokémon: Let's Go, Pikachu! and Let's Go, Eevee! (2018) - Game Design
- Pokémon Sword and Shield (2019) - Battle Planning
Generations I, III, and VII
A character named Erik (Japanese: コージ Kōji) may be a cameo of Kōji Nishino in the Japanese version of all Generation I games, as well as their Generation III and VII remakes.
He is found in Fuchsia City, looking for Sara (Japanese: アツコ Atsuko), which may be a cameo of Atsuko Nishida; she is found in the Safari ZoneRBY/GO ParkPE. In the Japanese version, they failed to meet each other due to a misunderstanding on the word "とり" (tori), which is also a pun. Erik used a bird Pokémon to arrive at Fuchsia City ("tori Pokémon" means "bird Pokémon"), while Sara is waiting for him inside the Safari Zone or GO Park ("Pokémon tori" means "obtain Pokémon").
This pun was lost in the English localizations. Additionally, in the English version of the Generation I and III games, Sara says that Erik is her boyfriend (which is not the case in the Japanese version).
- Japanese version
- "Koji: Isn't that weird? Atsuko said to use a bird Pokémon to go meet her...but I can't find any bird Pokémon!" (literal translation)
- "コージ『おかしいな？アツコと ポケモンとりで まちあわせって…… とりポケモンが みつからない！"RBYFRLG
- "コージ『おかしいな？アツコと ポケモンとりで 待ち合わせって…… とりポケモンが 見つからない！"PE
- English version
- "Erik: Where's Sara? I said I'd meet her here."RBYFRLG
- "Erik: Where's Sara? I said I'd meet her here to catch Pokémon... But all I'm catching are some weird looks!"PE
In Black, White, Black 2, and White 2, Nishino appears in Castelia City in the Game Freak building. He also appears in the form of a Hiker named Nishino (Japanese: ニシノ) in Black 2 and White 2, who battles the player once per day.
Post-Hall of Fame
Pokémon Black and White
- "I'm Snorlax. No, no! I'm the Planner! I don't mean to butt in, but the item Leftovers is important, isn't it?"
Pokémon Black 2 and White 2
- "I'm Snorlax. No, no! I'm the Planner! I don't mean to butt in, but the item Leftovers is important, isn't it? It's pretty useful in battle. Do you want to battle and test it?"
- No: "No?! Really? My Pokémon are pretty, though..."
- Yes: "I like to win using my favorite Pokémon!"
- "Ah... I see... That was quite well thought out."
- "Awww! What great Pokémon! The great number of steps seems to have increased their trust in you... I hope we can battle again tomorrow."
- The Japanese name of Snorlax, カビゴン Kabigon is also based on the nickname of Nishino. Snorlax's appearance and gluttony were directly inspired by Nishino: as 'kabi' means 'mold' and Nishino had a habit of eating moldy food.
- In a July 2000 interview with the Japanese Nintendo Online Magazine about Pokémon Gold and Silver, Nishino stated that male Schoolkids grow up to be Super Nerds, while Lasses grow up to be Beauties.