As the term drew to a close, my thoughts returned to the staff parties I went to during my three years in Japan.

The Japanese school year begins and ends in spring. Teachers can volunteer to change school, but no one chooses which school they teach at next, so it’s a tense time. With a fluid and sometimes reluctant staff, leaving and welcome parties are important team-building exercises, and despite their apparently formal nature, break the boundaries of cliques and hierarchies.

Before entering the dining room, each guest draws a number, or the name of a table, to determine where they sit. Those leaving or arriving have already been allocated seats. No one pours their own drinks - to do so labels you a drunkard - so offering someone a drink is an unobtrusive way to start a conversation. Your glass is never empty; you have no idea how much you have drunk, and by speech-making time there may even be a few alcohol-fuelled hecklers.

Leaving parties end with a walk down a tunnel of your colleagues’ arms, but after every formal party there is always a second, more informal, gathering. Allegiances and alliances become clearer.

After one party, when the men had disappeared to the next dive, the women slipped into a cocktail bar. The head had declared himself horrified to hear that many of the new teachers would be women, who, according to him would “work less than men”, and the secret second party was a chance for the female teachers to safely vent their frustration at an openly sexist system. It was also a chance to become more annihilated.

My favourite drunken memories are of karaoke and butt wrestling. “My Way”, “El Condor Pasa” and anything by the Carpenters are middle-aged Japanese teachers’ karaoke staples, but it’s “Kinta” that sticks in my mind. The singer was an outwardly respectable member of the municipal board of education, but the song would have made a rugby player blush. In every verse kinta would be followed by ma, making kintama, Japanese slang for testicles. The verses became more graphic, and the teachers increasingly embarrassed, but I felt honoured to have heard such a cringe-making example of Japanese culture.

I feel the same pride every time I see my butt wrestling certificate. At the end of the calendar year Japanese workers hold “forget-the-year parties” called bounenkai. Butt wrestling was the highlight of my first.

The 100-odd staff of the high school I worked for descended on a spa resort for a night of feasting, drinking and bathing. After speeches and skits, a low, wooden stool was brought out, and names pulled from a hat. Teachers came out in pairs, stood back-to-back on the stool, and when the MC shouted “Go!” tried to push their partner off with their behinds. My certificate is not for winning, but for effort and style.

Jennifer Moriya worked in Japanese schools for three years as an assistant language teacher. She will soon start a PGCE in modern languages at Middlesex University