The Emperor started Penguin Logistics with Texas in the year 1092. "Code of Brawl" takes place five years later.

We're not sure exactly when the Emperor hired Croissant and Sora, only that he did so in that order, in the first year.

Croissant: When ya first got here, there was always all kindsa presents pilin' up in front of Penguin Logistics. Mailboxes stuffed to burstin' with fan mail. (source)

The phrasing of this line suggests Mostima was hired before both of them.

Croissant: Tell ya the truth, I barely seen heads or tails of her since they hired me. (source)

But when Mostima asks how long it has been since she last met Texas, Croissant, and Sora, Exusiai answers: "Four years and three months" (source).

As a reminder, Penguin Logistics has been in business for only 5 years at that point, and only Texas was with the company from the start. Mostima could have spent a maximum total of 9 months with the PL girls. And given her regular duties to Laterano, it's unlikely that she did.

Though in that same linked chapter, Sora confirms that she's at least familiar enough with Mostima to have seen her cast Arts more than once:

Sora: No matter how many times I see it, I'm always impressed how Mostima will wave her staff around all light and subtle, only to have some big amazing thing come out.

[Which, when combined with the general sense of familiarity Sora shows towards Mostima at earlier points of the event, leads me to dismiss the canonicity of Sora's lack of familiarity with Mostima in Exusiai's second Operator Record. Which was already on thin-ice with regards to Sora by having this internationally-known idol accuse her agent of treating her poorly "just because I'm an up-and-comer…" (source)]

Mostima leaves Penguin Logistics again after "Code of Brawl", and while she visits Lungmen at least twice more before the events of "Guiding Ahead" in her first Operator Record and in the main story (appearing before Chief Wei Yenwu with a cryptic message about "breakfast"), she does not meet with the girls.

By all appearances, Mostima does not meet them again until Exusiai's second Operator Record, set after "Guiding Ahead", which is two years after "Code of Brawl". And then Mostima vanishes back to her usual duties until Exusiai meets back up with her in Laterano for the events of "Masses' Travels".

Meanwhile, Bison has spent much more time with Penguin Logistics than just that one crazy Sauin night.

By the time of the New Year's Day celebration later that year, Sora and the girls were inviting Bison to join them for their exclusive picnic party. And that was before his father hired them to spend the day trying to get Bison to relax and enjoy himself. (source)

According to many of his voice lines and archive files, Bison spent an extended period of time aboard the Rhodes Island landship at the same time as all four Penguin Logistics girls. His father wanted Bison to get some outside experience and not return "back at his side too early".

During this period, Bison actively sought out contact with the Penguin Logistics girls, and gained something of a reputation as their "poor whipping boy". He would try to keep Exusiai from disturbing the peace too much with her Heavy Metal party music, and help the Doctor clean up her messes, while accompanying Croissant on her shopping trips to try to keep her from making bad purchases, and recommending Sora's latest music publications to the islanders.

Angelina refers to this period in her first Operator Record, when she and Croissant talk about how they pranked Bison.

At some point, Penguin Logistics returned to Lungmen and Bison parted ways with them to visit various nations on behalf of his father's business: Kazimierz, Laterano, Columbia, Sami, Siracusa... And at the end of it, he returns home to Lungmen for the PL girls to throw him a welcoming party. When rival gangs attack the party, Bison resolves to himself that he will make Penguin Logistics operate like a normal company for at least one month, maybe even a year. (source)

After the events of "IL Siracusano", according to Texas Alter's third Archive File, Croissant reaches out to Bison for help in connecting Nuovo Volsinii to the rest of the world through his international logistics company.

Though it is called Mountain Dash Trade at that time, the timeline suggests that it is actually MountainCom Trade, after the events of "So Long, Adelle".

During those events, the Emperor meets Bison personally for a conversation. (source)

One year later, when Texas arrives back in Nuovo Volsinii for the events of "I Portatori dei Velluti", she explains that the reason Croissant didn't come with her is because "Croissant is busy pushing Bison into organizing some new international project". Which is apparently different from the previous one involving Nuovo Volsinii.

Later, during the events of "Masses' Travels", Bison comes up repeatedly as one of Exusiai's close friends. A gift from him is given equal attention as gifts from the girls, and his is the first she opens. When she rattles off the names of these close friends, Bison's name is not the last of the list (source). Nor is it when she rattles off the names to her sister. (source)

It is canonical, according to that scene, and her conversation with Agenir, and Texas' comment in Exusiai's promotion archive file, that Exusiai "seems to get along fine with anyone, but lets very few people close to her."

She has apparently allowed Bison to get close to her.

So, for all of these reasons, if Mostima qualifies to mechanically belong to both Lungmen and Penguin Logistics as well as Laterano, and Titi gets to be a honorary Minoan in both story and gameplay, then Bison deserves to belong to Penguin Logistics as well as Lungmen.

=====

JUSTIFICATION:

"Was sent off by her father to intern with the resident armed lesbian polycule/delivery company Penguin Logistics to gain life experience in the first event she shows up in (image one). She parts ways with the group afterwards because she doesn't mesh with the group but feels like she has grown, with the subtext of it being gender envy (Expresses jealousy with one of the more independent members of PenLog, Mostima). [https://64.media.tumblr.com/8c60e4ba160d641b2561181ee4d1285e/56fb75b84e75e5f9-c8/s1280x1920/d3708d8d132e9765283c162b30f5424fd173d531.jpg]

In the second event (image two) she shows up dressed as, in the words of a friend, "A transfem tourist on a business vacation" (I mean fucking look at that outfit and tell me she does not dress like a lesbian).

Also she has been called cute by a couple different shop owners." - @foxgirl-warcriminal

Reminder: Submissions are always open! Submit here!