Their relationship could develop realistically through shared interests. For example, if they both like a certain type of music or anime, they can start conversations about it. Then, these conversations can lead to them spending more time together outside of work.
One idea could be that Haida finally gathers the courage to ask Fenneko out on a date. They could go to a karaoke bar where Aggretsuko also works part - time. Another plot could be that Fenneko discovers Haida's secret hobby and they bond over it. For example, if Haida likes to paint in his free time and Fenneko stumbles upon his paintings.
The fanfiction could start with Haida writing a love letter to Retsuko but being too shy to give it to her. Meanwhile, Retsuko has been noticing Haida's kind gestures towards her. One day, Retsuko accidentally finds the letter. She approaches Haida, and he is mortified. But Retsuko tells him that she has feelings for him too. They then start dating, going on cute dates like picnics in the park and visiting local coffee shops. However, they face some challenges when Retsuko's over - the - top mother gets involved, but they manage to overcome it together.
One common theme is probably their relationship development. It could be about how they slowly fall in love or overcome obstacles in their relationship.
One common theme is the unrequited love. Haida has feelings for Retsuko, and many fanfics explore his attempts to get closer to her while she might be oblivious at first. Another theme is their shared work experience. They both work in the same office, so stories might revolve around office politics and how they support each other through it.
One interesting scenario is when Haida gets sick and Retsuko takes care of him. She makes him soup and sits by his bedside, and during this time, they have deep conversations that bring them closer. Or perhaps they both volunteer at an animal shelter. Retsuko loves the cute animals and Haida enjoys helping out. Working side by side, they start to see each other in a new light and develop romantic feelings.
Often, themes like love and friendship in the context of their relationship are explored. Since they have different characteristics, the fanfiction might focus on how they overcome differences. For example, Haida's shyness and Mommy Retsuko's more assertive nature could lead to interesting storylines about compromise and understanding. Also, there could be themes related to family acceptance if the relationship progresses in the fanfiction.
One great Aggretsuko Retsuko x Haida fanfiction could be about their adventures outside of work. For example, they might go on a hiking trip together and during that journey, they discover new things about each other. Retsuko could share her love for heavy metal music with Haida in a more natural and open setting, away from the office stress.
I'm not sure of a specific one to recommend off - hand. You could try searching on fanfiction websites like Archive of Our Own. They usually have a large collection of different fanfics for various pairings, including 'haida x retsuko'.
There are many fanfiction platforms out there, but finding 'haida x mommy retsuko fanfiction' might take some time. First, check the official fan communities related to the series. They might have some links or discussions about such fanfictions. Also, Reddit could be a good place to ask for recommendations from other fans of the show.