Random headcanons involving the Fukuzawa/Ranpo/Yosano trio
(Most of the following involve these 3 during the first years of the ADA because young RanpoSano living under Fuku's care is something so precious to me 🥹)
Yosano was given her work clothes by the ADA members, just like Atsushi (canon fact). My headcanon about this is that Ranpo got her the gloves and the tie, while Fukuzawa was left to deal with all the rest
^ Even though her size has changed over the years, Yosano still keeps the gloves Ranpo gave her as a souvenir
Yosano used to call Fukuzawa "Fukuzawa-san" up until she asked him to teach her combat techniques, calling him "Fukuzawa-sensei" ever since
^ The day she asked him to take her as an apprentice and used the appropriate "sensei" honorific in doing so, Fukuzawa was so moved his usual mask of composure fell off within seconds and he nearly cried
Ranpo was (and still is) always very clumsy and would often maim himself by tripping and falling on almost everything. After she started to live with him and Fukuzawa, Yosano was always the one to treat his wounds. One day, Ranpo suggested out of the blue she should become a doctor, given how good she is at nursing. This is partly the reason why Yosano decided, a few years later, to take medical classes to obtain a degree
After taking Yosano under his wing, Fukuzawa started to notice Ranpo was acting softer and slightly calmer whenever he was interacting with the young girl. Intrigued (and slightly worried), he checked his "How-to-raise-a-young-child" guide (the one from that WAN chapter I don't remember the exact title of that book sorry). One page read: "Your once turbulent child may grow some sense of responsibility and earnestness when having to take care of a younger sibling and/or friend". On this moment, Fukuzawa saw Yosano with brand new eyes: with her help, maybe there could be a way, a hope to finally tame Ranpo's restlessness, make him drop his childish behavior, and finally grow up
^ Sadly for him, Yosano turned out to be just as chaotic as Ranpo, and would rather follow him in his shenanigans than actually try to reason or stop him (sorry Fukuzawa)
While Ranpo doesn't mind people mistaking Fukuzawa for his dad (and even secretly likes it), Yosano hates it for some obscure reason she refuses to elaborate, and denies it every chance she gets. Especially during her late teens/early twenties. She had quite the rebellious phase during that period.
^ "We need to talk about your tendencies to break the bones of your fellow classmates whenever they annoy you." "Are you saying this as the Agency's President or as a regular adult?" "...what." "Because I may or may not listen to you if you are lecturing me as my boss. Otherwise I have nothing to say to you. You're not my dad, old man."
^^ (She has calmed down within the recent years, though she still have the typical father/daughter arguments with Fukuzawa sometimes)
Back in the very first years of the ADA, Fukuzawa used to give more headpats to Yosano than Ranpo (mostly because Yosano was (and still is) more diligent and serious in doing her work than Ranpo). This caused a lot of nipicking between the two teens.
^ Yosano already didn't like receiving headpats (in relation to that I-like-you-but-back-off-you-re-not-my-dad vibe she had going on with Fukuzawa), but she even started avoiding Fukuzawa for a while because she feared Ranpo would grow jealous of her because of something she didn't even want in the first place.
^^ "Like I would be jealous of you just because Fukuzawa gives you more attention, is always super caring for you, and praises you all the time without you having to ask for it..." (awkward silence) "... you are jealous, aren't you..." "No! No." "..." "... Or maybe I am. Just a bit. A tad bit."
^^^ Fortunately, Fukuzawa quickly took the hint of what was going on. Here again, his Bible (aka the how-to-raise-your-child guide mentioned earlier) saved him from more trouble...