Miyuki and Dazai’s first meeting wasn’t at the time of Miyuki’s joining, instead it was before. Coming across a figure on the bridge, Miyuki’s reaction was expected as she rushed to stop them. Forcing them down, Miyuki expected to be thanked for her interference and instead was surprised by the annoyance directed to her by the male. Completely baffled by his reaction, Miyuki could only listen in confused as he went on about comitting a beautiful suicide. Coming to terms with the fact that maybe she should take him to the police, Dazai quickly stopped her when she voiced this going with the fact he was fine and ‘in a good state of mind’. Still doubtful of this but not pushing it, Miyuki resolves to at least treat him to something to eat, with him accepting a little too quickly for her liking, before going on her way quite dumbfounded on the entire situation as a whole. She was greatly surprised to see him again once she officially became a member of the agency as she outright said that she was surprised that he actually had a job, which earned a chuckle from him as fegined being hurt by her assumption. Unsurprised with his personality as she already had a taste of it, Miyuki found herself amused and the two were able to develop an easygoing relationship since conversating was easy for the two and they worked well with each other’s pace. While she does find him somewhat strange this would later pipe her interest in getting to know him.

By the start of the story, the two have a nice friendship. Dazai finds great enjoyment in distracting the female from her work much to her annoyance while Miyuki can sometimes get him to actually do his job, sparing Kunikida the trouble of doing so. Because of this, she’s usually the one to collect the male after one of his numerous suicide attempts, usually chatting about his latest technique and her rejecting his invitation for a double suicide. While she mostly took him lightly, Miyuki always finds herself impressed when he actually takes something seriously, from his sharp wit to his meticulously thought out plans. As it was a stark difference in her mind from his usual behavior, Miyuki found herself growing curious. Just who exactly was this man? With Dazai, he noted the fact that Miyuki had her guard up about her past occupation and what led her here, made apparent when she grew closed off when Atsushi was guessing their previous occupations. The male had an inkling of what she'd done and was more interested in finding out exactly what it was.

Hiding her intentions on sedating her curiosity behind a simple invitation to lunch, Dazai was quick to see through it and teased for it asking her if she was asking him on a date. Despite herself, Miyuki’s reaction was extremely flustered as she quickly denied it. Amused with her reaction, Dazai took her up on her offer after telling her that he was joking. From there, their little outings soon became a routine for two; when neither were particularly busy they would go out for lunch. Miyuki was aware that he knew her true intentions while Dazai noted that she realized this early on. Eventually pointing this out after a couple of their little ‘lunch dates’, she instead proposed a sort of game. They both can ask one question and the other can only answer yes or no. Of course, she won’t be able to tell if he was lying or not but at least it would give her a general idea of where to start. Highly amused by her ambitious behavior in learning more about him, Dazai agreed to play along and from there two began an almost strategic back and forth. Miyuki knew that she would essentially be pulling teeth to get him to talk about himself, she was still optimistic as her questions mainly were used to test how far she could go before hitting a wall. Dazai however had little problem in learning about her as he didn’t need much to figure out what he wanted to know and both knew this. He wasn’t entirely mean though, he did give little bits of info to push her in the right direction but he never outright gave her solid answers.

It was through these little instances the two did that allowed Miyuki to slowly relax with him. Figuring out that Dazai knew why she was sent to the ADA, the female asked him if he found her repulsive because of it; most people that knew always looked at her differently as if she was no better than those she pursued. To her shock, Dazai simply laughed and at her inquiry, the male rather coldly that it was simply ‘child’s play’ compared to what he has done before. The cold tone and almost sinister expression left her in fear, the male watching her process what he said and putting it together with the few questions he answered honestly before figuring out his past occupation. With a smile that didn’t quite reach his eyes, Dazai threw her question back at her; did she find him repulsive for what he’s done. It took her a second to gather her thoughts before she looked him dead on and told him no. Miyuki figured that he was with the ADA in order to change, just like her and for the first time Dazai found himself taken off guard. There was no sense of hesitation in her gaze and he couldn’t help but chuckle, stating that she had ‘strange taste in people’. From there, the two still went out from time to time as Miyuki liked the company, chatting about nothing.

At the start of the Guild Arc Miyuki is aware of the growing attraction she felt but did nothing about it as more important things were going on. It was conflicting as she was almost assured that it was one sided and it wasn’t something that she needed to put much stock in. Dazai of course noted her change in behavior towards him but said nothing of it. This would only be brought up once Dazai gets shot. While Myiuki knew that it was on purpose, the female still couldn’t help but be frustrated with the fact that she wouldn’t have even known if she hadn’t overheard. Visiting briefly due to a time crunch, Dazai was expecting to see the angry crease of her brow and tight lipped frown and it proved to be correct. With a off handed comment of how such an ‘ugly’ expression didn’t suit her, Miyuki surprisingly kept her composure; the female just asked why he didn’t tell her. Brushing it off with a dismissive tone of it wasn’t important, the last of her patience disappeared. Grabbing him by the shirt, injury in mind, she told him flat out; “It is important, because I like you asshole!”

It wasn’t something either expected her to say and before it could be addressed properly, Miyuki caught herself and hastily made an excuse to leave. It wouldn’t be brought up until the end of Cannibalism. Approaching him after Atsushi went to get food, the two were in silence as they viewed the coastline. Miyuki breaks the silence by admitting he looks rather nice in a suit, earning a compliment in return about her own attire leaving her flustered. Their conversation was casual, speaking of the events that transpired and the aftermath of it all Myuki, with hesitance, brought up what she said to him at the hospital. She stood by what she said, adding to it that even if he didn’t view her like she did him, she still wanted him to know. A moment of silence passed after her words before Dazai simply let out a small laugh. Sparing him a glance, she was surprised with the smile that graced his features as they made eye contact.

“When I’m with you, my days get a little brighter.”

It took her a second to react to his words, the full extent of the meaning behind it hitting her instantly before her expression turned to one of pure embarrassment. From that point on, there wasn’t a notable change in their relationship or general dynamic; Dazai still enjoyed teasing him and Miyuki still took him out for lunch if he actually did his job but sometimes they both can be found looking at each other with a fondness that wasn’t present before.