Notes:

Topics which few people take in consideration about Haida:

*In the original shorts, he is mostly a cameo character who hardly had lines with few main appearances.

*In the Netflix version, Haida have unriquitted feelings for Retsuko who usually avoid him and hid things about herself .
She even went far to the point of knocking him out in episode 8 in order to make sure he’ll forget her confrontation with Director Ton.

*The reasons which Retsuko avoid Haida have been show in the first episodes since Haida was shown to be gullible, impulsive and reckless.
After all, he believed in a silly rumor that Retsuko gave birth a day before and said it loud in the middle of the work place which led her to be annoyed. He also showed to be jealous and aggressive toward other co-workers like Ookami, regardless of not even dating Retsuko, and wanted to punch Resasuke just because he was going out with her.

*Haida was also shown to be obsessive toward Retsuko to the point of wanting Fenneko to prevent her from going to the mixer organized by Tsunoda, however she would go anyway since she would only consult Washimi and Gori whose she trusts the most.

*Due Haida’s own jealously, he went heart broken and drunk to the point of laying in a puddle of water during a rainstorm which led him to caught pneumonia.
When Retsuko visited him, Haida spoke about “that guy from the sales” (a obvious reference to Resasuke) and she blushed as if he approved the relationship, however he was just being jealous.

*Haida showed to be rather selfish, since he tried to convince Retsuko to break-up with Resasuke so they could date instead.

*Although the dialogue is not shown in the hospital scene, Retsuko says that people should work through their discontent and move forward.
That was a clear reference to Haida whose she turned down.