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Code Lyoko Wiki

Some characters in the show have (or had) diaries. These characters are Ulrich Stern, Jeremie Belpois, Franz Hopper, Sissi Delmas, and Yumi Ishiyama.

Ulrich and Sissi's Diaries[]

Ulrich's diary was seen in Log Book, and Sissi stole it from him to use as blackmail to get him to date her. Yumi stole Sissi's diary in order for Sissi to tell her where she had hid Ulrich's diary. The entire story revolved around "log books."

Ulrich's diary had a dark green cover.

Sissi's diary was pink with an orange rhombus on the cover similar to the colors of her blouse. Only two pages were shown, one with a picture of Ulrich and other with a drawing of Sissi stealing Ulrich's diary. Also Yumi read a page of Sissi complaining about Jim.

Yumi's Diary[]

A similar episode to Log Book was Season 4's Lost at Sea. See episode description for details. Only one page is seen, which contains a picture of Ulrich. It was black with pink flowers in the cover and Hiroki took it from his sister to get a news story for Milly, but he accidentally dropped it and Ulrich and Odd found it and helped Hiroki to return it and reconcile with his sister.

Jeremie's Diary[]

Unlike his other friends' diaries, Jeremie's diary is composed of video logs. This was first seen in Temptation when he explained how he learned how to logarithmically boost his intelligence using a neuronal headset in conjunction with returning to the past. Jeremie's diary is also seen in the prequel, X.A.N.A. Awakens, in which he begins chronicling his activities at the factory. This diary makes a final appearance in Echoes, where it it revealed that Jeremie kept a comprehensive log of the adventures of the Lyoko Warriors as well as each of X.A.N.A.'s attacks.

Franz's Diary[]

Franz Hopper's diary plays a crucial role in Season 2, as it explains everything about the creation of Lyoko and X.A.N.A.. This diary also confirmed that Aelita is his daughter, and not a virtual being. It was first discovered by Jeremie and the gang in Mister Pück when Aelita finds a key inside her doll Mister Pück. This key opens a train station locker containing the diary entries on a large set of CDs. In the same episode, X.A.N.A. destroyed the CDs by possessing Jeremie, though thankfully he backed them up digitally within the Supercomputer prior to this. Jeremie's goal for much of the second season was to decode Hopper's diary, which he finally did in Revelation.