The third season of Re:Zero kara Hajimeru Kyuukei Jikan (Break Time).

The third season of Yoru wa Neko to Issho.

For various reasons, Mr. Ainz and Shadow-sama have swapped bodies! 
--But no one has noticed! 
It doesn't matter if the master has switched! 

"Overlord" and "Kage no Jitsuryokusha ni Naritakute!" Halloween collaboration of two anime series with chibi characters! 
(Source: YouTube Description, Translated)

The second season of Kage-Jitsu! mini animations, the shorts were initially broadcasted on television, then uploaded onto the KADOKAWA Anime YouTube channel.

A short animation of the TV anime "SYNDUALITY Noir" posted on the EMOTION Label Channel. 

Special episode of Yoru wa Neko to Issho promoting GAMERA: Rebirth.

Welcome to Snack Basue! Delight yourself in this charming snack bar, just five stations away from Hokkaido's largest downtown area, Susukino. Run by the quirky proprietress, Basue, and her junior hostess, Akemi, the place is filled with laughter and smiles from its oddball regulars and walk-ins as they regale tales of their lives. So, pull up a seat and have a drink—is shochu OK? 
(Source: Crunchyroll)

The second season of Yoru wa Neko to Issho.

Mini animations featuring characters from the Kage no Jitsuryokusha ni Naritakute! anime posted on the KADOKAWA Anime YouTube channel.

The fourth wave of parody shorts for Overlord IV airing on AT-X immediately following the main broadcast, later streamed on Kadokawa's official YouTube channel as a limited viewing and also going to be included on the Overlord IV Blu-rays. 

Note: Each episode is only available on the channel for a limited time, spanning 2 weeks long from the upload date.

When Fuuta comes home tired at night, all he wants to do is spend time with his new cat. All the mysterious habits and mannerisms of house cats are carefully reproduced in this relaxed and cute comedy about living with an adorable furball! 
 
(Source: Yen Press)

Chib Reve depicts the daily lives of the five Mizo middle schoolers and the Tokyo Manji gang members, which are not depicted in the main anime. 

(Source: Tokyo Revengers official website, translated)

The second cour of the second season of Re:Zero kara Hajimeru Kyuukei Jikan (Break Time).

Short animated advertisements with the characters from Agukaru promoting the 2013/2014 Governor and General Assembly elections for Ibaragi prefecture. 

(Source: Minoru Ashina)

Chibi shorts included in the Blu-ray release of Macross Delta: Gekijou no Walküre.

Sequel to Agukaru that was streamed on YouTube and niconico. Includes Episode 0: Prologue

A chibi-style quiz show featuring characters and questions from the anime ID-0 released on Bandai Visual's YouTube channel.

Each television episode of Chain Chronicle: Haecceitas no Hikari aired weekly with one of 12 "Chein Kuro-Nikuru", a wordplay on Chain Chronicle's Japanese pronunciation and the Japanese term for black shorts.
 
(Source: Anime News Network)

The digital sale/airing of the Chain Chronicle: Haecceitas no Hikari movies includes its own unique version of the Chain Chronicle chibi shorts, different from the chibi shorts shown with the theater airing. Their focus is on the female cast.

The second season of Re:Zero kara Hajimeru Kyuukei Jikan (Break Time).

The homeroom class gets sucked through a wormhole into - you guessed it! - another world where they encounter a desolate environment dominated by a rampaging magical automaton. There they meet a girl-type golem with mannerisms similar to Megumin, a woman dressed in the same military uniform as Tanya, and a man with a cane who seems to know Subaru, and hijinks ensue. 
 
(Source: Crunchyroll)

Short specials bundled with the Blu-ray volumes.

Studio PuYUKAI