Tomodachi Collection

Following the Wii's release in December 2006, the project restarted as Tomodachi Collection around April 2007. Developers sought to create entertaining gameplay that emphasized the human-like characteristics of the Miis, whom players were incentivized to create in the image of their real-world friends and family. Released solely in Japan on June 18, 2009. It received contemporary and retrospective praise for its unconventional tone and presentation. A domestic commercial success, selling 3.2 million copies by March 31, 2010, making it one of the best-selling DS games. Plans to localize the title overseas never came to fruition, largely because the Miis' voice synthesis program was unable to replicate English. It spawned the Tomodachi Life series beginning with a direct sequel, Tomodachi Life, that was released in Japan in 2013 for the Nintendo 3DS and internationally the following year. Another sequel, Tomodachi Life: Living the Dream, released on the Nintendo Switch worldwide in 2026.

Tomodachi Collection is a social simulation game featuring Miis, user-customizable avatars, who populate an apartment complex on an island. To add Miis, the player can transfer existing Miis directly from their Wii to their Nintendo DS, import Miis from other players' DS consoles via wireless local connectivity, or create new ones from scratch using the in-game Mii Maker. In any case, the player manually modifies their Miis' appearance and personality. There are four temperament categories Miis can occupy, which, together with their assigned date of birth, determine an "ideal job" that matches them. The Miis audibly speak through computer-generated voice synthesis. A maximum of 100 Miis can live on the island at once. After creation, Miis request assistance with particular problems, signified by the presence of a thought bubble. These issues include asking for food, clothing, guidance on prospective relationships, and player participation in short minigames. Satisfying their needs advances their level, a numeric progression system, upon which the player can gift them new clothes, interior designs for their apartment, personalized catchphrases, or songs for them to perform. Completing minigames awards the player with valuables that can be exchanged for in-game currency. The player can optionally eavesdrop on the Miis' dreams while they sleep. Tomodachi Collection has no end condition; the player's only goal is to maintain their Miis' satisfaction and passively observe their actions. Outside of the player's direct influence, the Miis regularly interact with one another, forming friendships and occasionally experiencing conflict. If two friendly Miis are romantically attracted to one another, one can confess their love to the other; if the confession is successful, the two are paired as a couple. Marriage can occur following additional interactions. As the player continuously appeases the Miis, new venues and shops on the island become unlocked. These include a Career Hall where jobs are formally assigned to Miis, a Compatibility Tester that gauges two Miis' likelihood of friendship, and a vendor for purchasing apartment interiors. An in-universe news broadcast occurs regularly to inform the player of recent events on the island. Time-sensitive events held by the Miis also take place in the island's fountain. Time on the island passes parallel to that set on the player's console, even when the console is powered off.

Tomodachi Collection was first conceptualized around October 2005 by a small team of junior employees at Nintendo SPD. Its premise was inspired by the fortune-telling video game Tottoko Hamtaro: Tomodachi Daisakusen Dechu (2000), published by Nintendo for the Game Boy Color in Japan. Tottoko Hamtaro, whose core audience was young girls, had users register a list of virtual profiles of close friends to measure compatibility and generate predictions about their day-to-day lives. Producer Yoshio Sakamoto agreed with some female employees' idea for a derivative version of Tottoko Hamtaro geared to older women, the thought of which "stayed with [him]"; he would then find himself "in a team made up of all new people and we were relatively free to do what we wanted". With the dual purpose of elevating the Nintendo DS' overall appeal to women, the project became tentatively known as Otona no Onna no Uranai Techō (大人のオンナの占い手帳, lit. 'Women's Fortune Telling Pocket Notebook'). Initially including only textual information about personal names and birthdays, the team resolved to add a three-dimensional character creation mechanism. This system—inspired by the Japanese game fukuwarai, which involves assembling a face using disembodied parts—had players manually combine selected face elements to create caricatures of real-world people. The ability to rotate, resize, and reposition facial features was added, enhancing the character creator's accuracy. Sakamoto demonstrated the prototype to Nintendo president Satoru Iwata early in 2006. Iwata further relayed it to Shigeru Miyamoto, who was working on the then-upcoming Wii console with a separate development team. Miyamoto had petitioned for the inclusion of character-creation mechanics in Nintendo consoles for more than a decade, starting with the Famicom through the GameCube, but encountered design limitations and internal company pushback. At the time of the Wii, he was experimenting with including kokeshi doll-like avatars in Wii Sports (2006). Upon viewing the DS prototype, Miyamoto told his coworkers, "You guys are useless," briefly switching teams to help develop the character-creator. During a trans-departmental meeting concerning the Wii's hardware, Miyamoto formally proposed the prototype be reworked as pack-in software for the Wii. Many of his peers expressed concern over the avatars, believing they were too rudimentary and often not particularly accurate. Additionally, much of the Wii's hardware had already been finalized, contributing to developer reluctance. Once hearing Miyamoto's reasoning that most users, young or old, would find joy in the creative process regardless of its limitations, most of the Wii staff agreed to implement the caricatures, which would become the Miis. Development on Otona no Onna no Uranai Techō stalled around August 2006 following its team's internal reassignment as lead producers of the Wii's Mii Channel, at the suggestion of Iwata. Leading up to the debut of the Wii in December 2006, director Ryutaro Takahashi re-envisioned Otona no Onna no Uranai Techō as a simulation title appealing to all ages and genders, since the DS had by then already gained popularity among women.

Tomodachi Collection was released for the Nintendo DS in Japan on June 18, 2009, with a demo version distributed through the Wii's Nintendo Channel, Nintendo Zone, and local DS Stations. To promote it, a television program titled Koi no Kaitou!? Tomodachi Collection II (恋のカイトウ!?トモコレ2世, lit. 'Love's Answer!? Tomodachi Collection Second Generation') featuring Japanese actresses Mari Sekine, Maaya Morinaga, and Rima Nishizaki alongside their Mii caricatures began airing on Tokyo Metropolitan Television on May 6, 2010. A television commercial featuring celebrities Keiko Kitagawa and Shihori Kanjiya also aired around the same time, with the game's official website updated to include tutorials for players on how to create Miis of the two. Nintendo considered localizing the game overseas, with the company reportedly having trademarked the name Friend Collection in Europe in 2009. This plan was scrapped when Nintendo discovered that the voice synthesis program used for the Miis' speech, built natively for Japanese, could not replicate the phonetic complexities of English. Additional concerns were raised regarding a potential lack of cultural appeal outside of Japan. Sakamoto stated in an interview with 1Up.com, "Obviously I can't speak to future plans, but [localization] seems like something we might be able to revisit once more powerful hardware comes along."

A sequel for the Nintendo 3DS titled Tomodachi Collection: New Life was released in Japan on April 18, 2013. Unlike its predecessor, Nintendo fully localized the game for foreign regions; it was released as Tomodachi Life in North America and Europe on June 6, 2014. Much of Tomodachi Collection's staff, including director Takahashi, producer Sakamoto, and art designer Mai Okamoto, returned to develop the sequel. The Japanese version featured an exclusive mechanic that allowed players to import existing Miis from Tomodachi Collection using a dedicated Nintendo eShop application. On October 31, 2024, Tomodachi Collection's soundtrack was made available through the Nintendo Music streaming service exclusively for Nintendo Switch Online subscribers. Another sequel, Tomodachi Life: Living the Dream, titled Tomodachi Collection: Exciting Life in Japan, was released on April 16, 2026, for the Nintendo Switch, with compatibility with the Nintendo Switch 2. Takahashi and Sakamoto reprised their roles as the key developers.