While Japan's train system is universally lauded as punctual and convenient, there's always that one person on the daily commute that ticks you off.
How many times have you stood on a crowded train with elbows jabbing into your back or a drunk businessman falling asleep on your shoulder?
It's tempting, but I don't recommend 腹を立てる (hara o tateru, losing your temper) or かっとなる (katto naru, blowing your top) while riding the train — the troubles that could result from a public かんしゃく (kanshaku, temper tantrum) are legion.