The Koirao or the Thangal inhabit in nine hill villages of Sadar Hill Areas of the Senapati District. The villages are:
(a) Mapao Thangal
(b) Thangal Surung
(c) Makeng Thangal
(d) Tumnou Pokpi
(e) Yaikongpou
(f) Tikhulen
(g) Ningthoubam
(h) Mayangkhong and
(i) Gailongde

The geographical extent of the Koirao areas is Angkallongde Karong in the north, Mapao Thangal in the south, I.T. Road in the west and Iril river in the east.

According 1981 census, the Koirao population was 2132. However, the tribal Benchmark survey, conducted by Director of Economics and Statistics, in 1982 reveals that the total population of Koirao was 1593 in 290 households.

The Thangal/Koirao is one of the historically important tribes as they have a claim as to be the birth place of the establisher of the present Manipur dynasty. They speak a dialect, which is more or less similar to those spoken by Maram, Liangimi, Ronginei. The literacy rate of the Koirao is very high.

Though majority of the households are engaged in wet cultivation, the shifting cultivation is still practiced. Government servants occupy next spot to agriculture in occupation.

Females constitute a good part of persons having secondary occupation and they engage themselves in various cottage industries (Weaving in particular. The agricultural implements are more or less similar with other foothill dwellers or plain inhabitants and include plough and yoke, adze, sickle, axe, dao etc.

The women, in social gatherings, use Mik Keap thoi, a skirt and shawl Tang Kol maphi while men use Khom'nei as loin cloth and a piece of cloth called Chak'rei across the chest.

The people believe that they come from a more northerly direction emerging from a cave. Their legend has it that there were three brothers whose parents were not known.

The eldest brother was the originator of the present tribe while the second and youngest brothers became originators of Tangkhul and Meitei respectively. From this folktale, their first settlement site was at the Kaipong range to the east of Maram in Manipur.

In the Koirao society, there are 17 lineages of which Kadei Keimei, Payei Naomei, Syong Duimi, Payot Naomei and Deibung Naomi are according to some persons, the oldest ones from which other lineages were separated.

The selection of mates is restricted mainly by the rules of lineage exogamy that the brides should be from other lineage groups. Though the Thangal is an endogamous society in the past, wives were acquired from outside the tribe.

The Koirao is a monogamous society besides being the typical nuclear family. Marrying a cousin from the maternal side through engagement is the usual type of marriage. This goes through a number of stages. The present frequently reported type is elopement. Bride price may or may not be given depending on the wish of the bride's party.
The Koireng inheritance rule is patri-lineal but ultimogenetiure. The traditional village authority was fully vested in a council, led by a hereditary office of Khullakpa. The council would be consisted of:
1) Khullakpa (chief)
2) Luplakpa
3) Kangpara or Ganpara and
4) Two Tans

Khullakpa was the chief and restricted to the Kaduikeimi lineage only.
After the Manipur village Authority (Hill areas) Act, 1956 the modification in the structure occurs as:
i) Chairman is always the Khullakpa
ii) Secretary is the Luplakpa
iii) Treasurer and
iv) Members

The calendar of traditional festivals in pre Christian Thangal society were as many as the number of the months. The majority of these festivals were related with their socio-religious belief associated with agriculture.

The full moon (Hadet) plays a vital role in fixing days. In the month of Kaphala (May), the first Thangal month, they observe two-day festival of Kapha worshipping Keirong-raiba for good health and prosperous society. In Jangheiha month (May-June) there are festivals of Imphoi Imphoi Dangnit, prayers to protect the seed-grain from pests etc, and Janghei, a two day festival to drive evil spirit, saraikagai.

The dance of this festival is Kakhoi Yagathou. In the month of Tundeiha(June-July) a ritual, Malangathou, is observed to call the soul spirit of paddy. In the month of Noudanda(July-August), the selected performer cuts the grass at main gate indicating the cutting of bad grass to give way for the good ones.

On this day, people cook chicken and refrain from doing work. From the next day, they start cultivation. In the month of Mathala (Aug-Sept), Malangathou is observed. This involves praying the deity for prosperity and growth of village.

Naogagathou genna is celebrated for the welfare of children praying the household deity Khumdung in Ganha (Sept-Oct). Worship of granary deity, Phouraiba by offering a cock of single colour and wine takes place in Torotakha (Dec- Jan).

During the month of Taha (Jan-Feb) a ritual offering to the departed souls during the proceeding year is observed on an auspicious day.

Giphiyotangatha, care of weapon and sharpening them, is held on the first or second day after the full moon of Giphiyoha (Feb-March). On the 24th day of Keithakha (March-April) the ritual of linhut Dangsit for seed sowing is performed.

After the advent of Christianity in 1946, the Traditional Thangal Festivals are no longer observed except few.