Goku Sayonara Zetsubou Sensei

"Is that a, uh, um, some reference?"
Basically shows referencing other franchises

(Note: Feel free to suggest more or to tell me if I missed something. This was made by someone who has not seen Gintama)

Somewhere in these entries a character that looks or acts like Michael Jackson appears.

Goku? Zan? A straight-forward list of the series that comprise the "Sayonara Zetsubou Sensei" anime saga.

These openings are the most unusual openings among all openings. They might either tell you nothing about what the anime is about or tell you in the most criptic way possible. They might use unusual music or animation.

Akiyuki Shinbo is a Japanese animator, director, compositional writer, and storyboard artist. Best known for his works with Shaft, he has attained international recognition for his unique visual style and storytelling methods.

Shinbo began his career in the early 1980s as an animator, but his true rise to fame in the industry occurred when he received the opportunity to direct for series produced by Pierrot at the turn of the decade and early 90s. His unique style developed across the studio's productions, cultivating in Yu Yu Hakusho, which led to his debut as a series director with the J.C.Staff television series Metal Fighter Miku (1994). Over the next several years, Shinbo developed his directorial style through numerous avenues in the industry; and the pure form of his style has been described as coalescing in series like The SoulTaker (2001) and Le Portrait de Petit Cossette (2004).

In 2004, Shinbo was invited by newly appointed Shaft president Mitsutoshi Kubota to collaborate with the studio as a director. Since the newfound collaborative effort's debut with Tsukuyomi: Moon Phase (2004), he has mentored various directors and won numerous awards for his productions with the studio. His notable directorial works with Shaft include the Monogatari series (2009–present), Puella Magi Madoka Magica (2011), and March Comes In like a Lion (2016–2018).

Part 1: https://myanimelist.net/stacks/51397
Part 2: https://myanimelist.net/stacks/51399