某 (ぼう, bou) is a unique Japanese term that is used in writing to refer to a thing or person anonymously, sometimes in a sarcastic way. In old Japanese, 某 also reads (それがし, soregashi) and means “I/me”; this usage is seen in period dramas.
某 is usually put before a noun, like 某アニメ meaning “the/this/a certain anime”. Basically, it is used when people want to refer to someone or something anonymously, but sometimes it is quite obvious what/whom they are alluding to, in which case it can contain a sarcastic tone.
某国会議員 (こっかいぎいん) に我々 (われわれ) はインタビューをした。
We interviewed a certain Diet member.
After I worked in the famous IT company in Shibuya for three years, I started my business.
I’m sick of hearing the news anymore that the celebrity had an affair.