To fill the void left by the merger, internet services companies Livedoor and Rakuten submitted applications to form teams to be based in Sendai, Miyagi Prefecture.

[6][4] The name is derived from the Japanese golden eagle, a large, endangered, predatory bird found in the mountains of Japan's Tōhoku region.

[9] The league's decision to employ an unequal dispersal draft to build the Eagles roster was blamed for the team's struggles to come.

[10] Rakuten was able to select former Buffaloes outfielder Koichi Isobe because he was left unprotected by Orix after refusing to play for their newly formed team.

[11] Just over a month into their first season, the Eagles removed Kuehnert as general manager and demoted the head and batting coaches following a 6–22 start.

With one of the All-Star games being played at the Eagles' home stadium that year, fans also voted in seven other Rakuten players, including rookie pitcher Tanaka.

[38] Kazuo Matsui and Akinori Iwamura, both returning from playing stints in Major League Baseball (MLB), were also added to the roster,[39] and Teppei Tsuchiya was named as the team's first ever captain.

[43] In addition to Rakuten holding fund-raising events,[44] all 12 teams played charity games to help raise money for earthquake relief.

[46] Furthermore, the final game of the 2011 All-Star Series was switched from Tokyo Dome to Miyagi Stadium, the second time the Eagles hosted the event since 2007.

[48] However, in addition to winning a Golden Glove and a Best Nine award,[49][50] Tanaka was also named PL MVP of the month three times over the course of the season, a first for the Pacific League.

[52] Rakuten went deep into the 2012 season as a playoff contender that year, but ultimately missed advancing to the Climax Series by one game and finished fourth.

[54] The team took sole possession of first place in the Pacific League in early July and never relinquished it, winning the Eagles' their first PL pennant.

[60] Starting pitcher Manabu Mima was named the Japan Series MVP after the series,[59] and at the end of the season, Tanaka was presented with the PL MVP and Eiji Sawamura Awards,[56] Norimoto was named the PL Rookie of the Year,[61] and Senichi Hoshino was given the Matsutaro Shoriki Award.

[63] Following the championship-winning season, Masahiro Tanaka left the Eagles via the posting system to play for the New York Yankees, netting the team a $20 million transfer fee in return.

[66] At the end of July, hitting coach Tomio Tashiro abruptly resigned and it was revealed that owner Hiroshi Mikitani had often been interfering in on-the-field decisions, such as dictating the batting order.

The turmoil brought about by Mikitani taking the lead on baseball operations after Hoshino's unexpected resignation forced Rakuten to reevaluate how the team was managed and organized.

It was decided that Hoshino, who had been retained as an Eagles vice chairman, would have full authority over baseball operations, similar to the role of an MLB general manager.

[69] The team, hoping to avoid a third consecutive last-place finish, hired veteran PL manager Masataka Nashida[70] and signed free agent Toshiaki Imae, a two-time Japan Series MVP.

[78] The Eagles went on to finish the season in last, however before it was over Rakuten formally created a general manager (GM) position in Hoshino's absence.

Former NPB and MLB pitcher Kazuhisa Ishii was hired in the role to help coordinate the efforts of the front office and field management.

[82] The next season, a third-place finish secured the Eagles a place in the 2021 PL Climax Series, however a loss and a tie against the Marines ensured that Rakuten would not advance to the final stage.

Their glossy helmets mimic the cap design and are created using a traditional Miyagi Prefecture lacquer technique called tamamushi-nuri.

Additionally, the raglan and side piping was removed in favor of crimson and gold stripes around the collar and sleeves and the font of the player's name and numbers was again modified.

[95] The club's current home jersey debuted before the 2020 season and is very similar to its previous iteration, albeit with the crimson and gold collar stripes removed.

In the garment's first iteration, the white Rakuten logo was wholly original and incorporated a yellow drop shadow to give it a 3D effect.

All yellow was removed leaving the logo completely white, and the font was changed to bring it in line with Rakuten's corporate branding.

Starting with the 2007 season, players wore special uniforms during a limited, home-game stretch dubbed "Fan Club Day".

For the 2019 season, Rakuten's fifteenth, the Fans' uniform was changed and again borrowed the home jersey design, however in grey instead of white.

The uniforms were worn during four interleague games that season, and the player-worn jerseys were auctioned off to raise money for earthquake relief.

[106] At the time of team's inception, Rakuten created a pair of unnamed male and female golden eagle mascots.