In the Academia, usage of syllabic abbreviations is quite a bit more common than in the general population, often incorporating English words with kanji in the same breath.  This makes their abbreviations somewhat obtuse for those not raised from birth in the Academia- a student may speak of going to Milmed (”military medicine”; slang for Academia’s own hospital), Detadep (”detainment department”; Academia’s Department of Inter-Dimensional Corrections), or to a number of differently nicknamed units.  Initialisms are generally preferred in more formal contexts because they more accurately portray the names of the departments, but the syllabic abbreviations live on in vernacular.

As well; many smaller divisions have earned nicknames or reputations among the Academia students for their deeds or dress, despite the Academia’s already relatively small size.  The most notable would be the Black Jackets; the entirely Synchro-born division, so called because of their distinctive uniforms, and the Ivies, officially called the Fourth Division, which contains most of the youngest combat-ready Academia soldiers.

Naturally, due to the heavy advantage of Fusion, communication within the Xyz Rebellion and Xyz as a whole are difficult.  There are several complicated ciphers in use, including the currently uncracked Barian glyphs/language.  However, the most simple form of Rebellion communication is through a mostly agreed upon set of symbols often found near foot level on buildings.  These are simple and similar to 1930s homeless code in some ways- the intent is not to convey complicated messages, but to warn others of potential danger.

The most common symbols are are an O (safe) and an X (dangerous; there are Fusion soldiers nearby).  Numbers are also used for various purposes, similar to goroawase (substitution of numbers for sounds).  29 represents a rebellion cache of goods (2-9, ni-ku, meat) for example, or 90 (9-0, ku-ma, bear) for dangerous wild animals such as dogs.

Rebellion letters are often simply marked 39 (san-kyuu, thank you) and returned to signify being read.

15 years ago, before the Xyz Invasion, was the first Fusion intervention in a different dimension.  That dimension was Synchro, which had suffered under an oppressive government for decades at that point.  Sensing a weakness to be exploited, Fusion sent their soldiers (mostly paid soldiers at that point and not members of the Academia) to topple the government and painted themselves as saviors.  Most members of the Synchro public, happy with the aid and easing of class boundaries, embraced the newly stationed Fusion army.

Fusion put Synchro-born puppets in control of the new government for optics but continued to benefit; in exchange for a relatively low amount of money they received weapons, manufactured goods, and new soldiers to be trained at the Academia.  (The Synchro members of the Academia are their own unit, referred to as the Black Jackets colloquially.)

Now, 15 years later, Fusion is somewhat entrenched in Synchro culture.  Fusion manufacturing is a large source of income for many families, and it’s not uncommon for wealthy members of new Synchro society to send their children to be educated in Fusion.  Many Fusion soldiers have been stationed there for years and have built their own families with the locals.

The people of Synchro are unaware of Leo Akaba’s plans to unite the dimensions.

The Heartland Wasteland is a dangerous place to be, not only because of the prowling soldiers.  There are many environmental hazards caused by the invasion.

The most obvious hazards are the lack of food and clean drinking water.  As the production of perishable goods has been destroyed or disrupted, the survivors have turned to eating primarily canned goods for survival.

As well, the burning of buildings has released both ash and carcinogenic building materials into the air.  Although most of the fires have long burnt out, much of this remains, leaving quite a bit of dust blowing in the air.  It’s considered common for Xyz survivors to have at least some lung damage.

Wild dogs are also a hazard, due to the amount of time having passed between the invasion and the present day, many former pets having bred and created feral children.  Due to the lack of resources in Heartland, they’re often aggressive and dangerous to humans, as well as a vector for disease.

Xyz survivors are often nomadic to deal with these conditions, traveling around the area and in rare cases between cities to find more food, escape the ash blowing in from the wind, and keep from disease.  A few groups have even retreated into the Japanese mountains to survive.

In the Academia, children are often taken to the Academia at the age of 3 or 4, sometimes younger.  The young children are taken care of by teachers/minders, often former soldiers themselves who were injured or retired due to age.

The most basic forms of military training begin at age 7, roughly in the first grade.  This is when children first learn simple dueling and physical exercise.  Over the years, training grows to include strict exercise, war games, and harsh dueling as well as more traditional academics (though those are less focused upon, especially foreign language and literature).

When a child is 12, they’re considered ready for large scale deployments, and are often sent to Xyz or Synchro.  Incidents of misconduct (by the Academia’s standards) are relatively scarce because of the life long conditioning and harsh consequences.

Academia students don’t use last names, instead using first names (written in katakana) and five digit student ID numbers.  (”Shiun’in” and “Mackfield” are fake names.  In Academia tradition, Sora Shiun’in’s name would be rendered “ソラ#58273″ or something similar.)

Nicknames are fairly common within the Academia to quickly tell apart two students with the same name, usually based on traits or ID number.   Two students named Hanako may be determined by names like “Blondie” or “Seven”, depending on what catches on with their classmates.

As well, Academia duel disks are activated through a small RFID chip registered to each student.  These can open doors based on clearance within the Academia as well as tracking the locations of students.  Each Academia RFID chip is inserted into a student’s right hand upon registry to the system, usually around age 7, when training begins.

The name and number system is indeed an attempt by the administration to keep down individuality, but it also has the administrative benefit of making individual students easier to keep track of without spelling or kanji errors.  Students view it as an equalizer; they are all part of the same family and no one is higher based on arbitrary family status.