The anime delves more deeply into the library's history, its connection to the local town, and challenges faced by the sisters.

Kokoro learns the meaning of being a librarian, meets her favourite author, and takes a family trip to the seaside.

The library is called "the place where miracles happen", although we see nothing more magical than Kokoro's ability to produce rainbows with her watering can.

Events take a dramatic twist when phantom thief Funny Tortoise steals a mysterious locked book which belonged to Kokoro's father, who died when she was very young.

The next episode is seen from the point of view of a young soldier named Sant Jordi,[a] during a war which has seen the town heavily bombed.

Kokoro, reading the story in what is revealed to be her father's diary of the war, finally has a connection to the parents she never knew.

"It's too late to train to become a manga artist now when you have the ability," he said, and pitched Takagi to the editor-in-chief of Monthly Comic Dengeki Daioh, whom he knew.

[9] We are never explicitly told the name of the country where the library is situated, or the year when the series takes place.

The names of the three sisters together form the phrase "kokoro aru to ii na," meaning "it's good to have a heart".

[16] Kokoro Library began serialization in the April 2000 issue of Monthly Comic Dengeki Daioh.

It was collected and published in a set of three A5 loose-leaf volumes between April 2001 and August 2002, under the Dengeki Comics Ex imprint.

Kokoro Library was reprinted in April 2013 in two smaller paperback volumes under the Gum Comics Plus imprint.

[26] The DVD release used the 4:3 aspect ratio and was notable for use of linear PCM audio rather than the lossy Dolby Digital format.

The CD also includes the ending theme "Tsuki wa miteru" ("The Moon is Watching Over Me") and off-vocal versions of each.

A Kokoro Library Fan Book was published on June 10, 2002, shortly before the release of the third manga volume.

[29] A piece of PC software was released, titled Communication Library Kokoro Toshokan (コミュニケーションライブラリーココロ図書館), which retailed for ¥5,800.

They included both dolls and 1/6 scale figures of the three sisters, at least ten separate posters, Broccoli trading cards,[32] a 2002 calendar, a mouse mat, pencil boards, a bookend, several telephone cards, a CD case, a watch, three pin badges, a memo pad, and even an official replica Kokoro cosplay costume produced by Broccoli subsidiary Cospa and retailing for ¥44,800 (equivalent to US$376 in 2002).

[34] Despite finding the "overall Kokoro Library experience enjoyable", Jeremy remarked that its "accompanying relaxed pacing" would turn viewers off.

The December 2001 anime song ranking placed Kokoro Librarys opening "Beagle" at #5, and the ending "Tsuki wa Miteru" at #8.