Before we move on, I think some things need to be clarified now. Otherwise you will have trouble understanding later.

You can skip this section if you want, but reading this section will help you to understand your context. But if you don't understand something in the future, you can always come back here and see. Perhaps, you may have learned a lot about the Japanese culture by watching Japanese animation. Also, maybe you learned a lot about Koreans from Korean Webtoons. So what's your loss now to learn something about the new culture? Once you understand, maybe you will find a lot of fun here, like anime or Webtoon.

It is a common sight either in a town or in a village. It is commonplace for all classes of people in any corner of this country. It is a small shop. In town, tea stalls are innumerable. Tea has now become a popular drink. So, A tea stall is usually crowded. 

Wherever you go in Bangladesh, you will find roadside tea stalls or "Cha Ghor" to offer tea and other light snacks such as biscuits, processed sweet buns, bananas, gum, cigarettes, etc. The person running the tea stall is commonly called Mama Uncle or Khala Aunt.

Tea stalls are not just tea stalls in here. It’s a part of culture, social ritual, and much more. Locals hang out and socialize here, deals are sealed, and friendships get started. Total strangers may offer you a cup of tea. 

Tea is served in small glass mugs, either with condensed milk or cow milk that has been boiled for long to concentrate, and always with lots of sugar. Multiple aluminum kettles are used to boil tea and milk at various stages over propane flames.

The taste comes from boiling strong black tea. Also, thick milk and lots of sugars, sometimes with ginger and some spices, contribute to the uniqueness of the taste. 

However, many of the local gangsters hassle the shop owners for money. Most of the times cops remain unresponsive to such cases. 

This is because the local political leaders mainly protected the local bullies. The police cannot say anything to political leaders.

Sometimes, the police themselves drink tea for months without pay.

Mess- This word originally means "A building or room providing meals and recreational facilities for members of the armed forces." However, it is used as an umbrella term here.

A dormitory.

A certain sort of flophouse/dosshouse. But it's a bit better than the flophouse because people here are on a monthly rental agreement. However, the monthly rent is comparatively very low. Much like a flophouse. It's the less fortunate rendition of the lodging. Or the poorer version of the hostel. Cheap hostel.

RAB- Notorious for crossfire. They don't hesitate to kill the criminals. They are also rumoured to have abused this power a lot. They wear black uniforms.

Thus yellow Himu, Black RAB is the name of this arc.

From formal source:

Rapid Action Battalion or RAB, is an elite anti-crime and anti-terrorism unit of the Bangladesh Police. 

The Rapid Action Battalion has been criticized by rights groups for its use of extrajudicial killings and is accused of forced disappearances.

Wordplay of "You"

If you are familiar with Japanese culture, you probably know that the usage of honorifics such "Sama" "Kun" "dono" "senpai" etc. 

If you are familiar with Korean, you should know about "Nim" "Oppa" "Hyung" "Ahjussi" etc.

Now, it’s time to learn something similar in my language.

[YOU]

Apni, tumi, tui- you have these three common words for "You".

 *Out of these 3, "tui" is the most controversial one and best to avoid using it.

Apni = respect, senior (you) 

Tumi = friendly 

Tui= close friend, junior, servants. You see why tui is tricky? This will appear many times in the novel.

Now, let's break them down to make them digestible.

 We apply these terms depending on the type of relationship and senior, junior. 

Apni:

We think that if you are a senior and a respectable person, I have to say "apni". 

If you are a stranger, I must greet you with "apni" as a form of respect regardless of your age. (Unless It's obvious that you are a kid or a huge age gap) Or else it would be regarded as rude.

If you greet everyone as apni, you are safe. It means you are overly mannered and a decent person. A true gentleman from higher society. Well educated and cultured who knows to respect all people. 

*However, sometimes people call their juniors "apni" as a form of sarcasm or to patronise them.

Tumi:

If you are the same age, but not too close. Formal. 

For an example a classmate you barely know - you can call them tumi. You also can call them "apni" but that would sound overly formal and strange since you are treating your classmate as some stranger. Your classmate may even get upset by deducing that you are not comfortable enough with them.

Even if you are not comfortable around your classmate, it’s a sign of manner to not hurt their feelings.

 Again, it displays the level of comfort in a relationship. 

 

Comfort wise

Apni < Tumi < tui. 

Apni is the least comfortable, and it means you simply won't open up. 

Tumi is the general comfort you feel towards the surrounding people.

Tui is just too much comfort. Like the bestie. Not a lover, by the way. Bestie means you are friendzoned. 

if you are a same age relative or friend, but not intimate enough to feel too comfortable = tumi 

That’s why in many romantic stories, this Apni to Tumi shift plays as a character development device to show that they are slowly feeling comfortable. 

Tumi can also be sometimes used for addressing parents, uncle, aunt etc relatives to show the friendliness or friendly relation. It means you have a healthy relationship and you are not afraid to open up to them.

However, kids who grew up from overly traditional family may disagree with this or even feel attacked. It's because they are used to the "apni" relationship with their senior family and relative members.

 If you are someone closer, close friend, intimate cousin, or a junior= tui.

If the junior is someone you barely know, it’s best to call them tumi instead of tui. It's because it can offend them. Why? 

 Again, the word tui is used in a trivial and angry way. It is used to show disgrace.

 For an example, if you are a noble talking to a servant, then you will call him tui. Greetings of highest class to the lowest class.

In terms of class: Apni > tumi > tui. 

So, if you call tui to anyone, they can assume you are putting them on an inferior level.

To recap: 

Apni = Higher level, superior / respectful to strangers, guests.

Tumi = equal.

Tui = inferior / or too much intimacy/ bestie / friendzoned.

Comfort : Apni < Tumi < Tui

Superiority: Tui < Tumi < Apni.