Three short films, directed by different individuals and lasting between 15 to 14 minutes each, make up Modest Heroes. The first film, titled "Kanini & Kanino" ("Kanini to Kanino") by Hiromasa Yonebayashi, is a fantasy adventure story about two crab siblings. It will be the longest of the three shorts at 15 minutes long. The second short, "Life Aint Gonna Lose" ("Samurai Egg"), directed by Yoshiyuki Momose, focuses on human drama and showcases the love between a mother and her son. Lastly, "Invisible" ("Tōmei Ningen") by Akihiko Yamashita is an action spectacle that follows the lonely struggle of one invisible man. These films are described as tales of modest heroes of our times by Studio Ponoc.
Chiisana Eiyuu: Kani to Tamago to Toumei Ningen was released in North America by GKIDS on October 10, 2018 and Blu-ray & DVD was distributed by Shout!Factory on June 18, 2019. It was released on Blu-ray & DVD in Japan by Walt Disney Japan on March 20, 2019.The movie was initially envisioned to consist of four segments, the fourth being directed by Studio Ghibli director Isao Takahata; however, due to his death on April 5, 2018, the movie was released with only three segments.