一人一人

ひとりひとり ひとりびとり

one by one, each, one at a time

一高一低

いっこういってい

rise and fall, frequent fluctuations (of the market price)

一宿一飯

いっしゅくいっぱん

(being beholden to someone for a favor of) a night's lodging and a meal

一得一失

いっとくいっしつ

gaining some and losing some, (something having its) advantages and disadvantages

一向一揆

いっこういっき

Jodo Shinshu Buddhist uprising (Muromachi and Warring States periods)

一点一画

いってんいっかく

the dots of i's and the crosses of t's, (not neglecting) the slightest details

一党一派

いっとういっぱ いちとういっぱ

particular party or faction

一言一句

いちごんいっく ひとこといちく

every single word and phrase, word by word

一つ一つ

ひとつひとつ

one-by-one, separately, in detail

一字一句

いちじいっく いち じいっく

word for word, verbatim, a single word and a single phrase

一期一会

いちごいちえ

once-in-a-lifetime encounter (hence should be cherished as such)

一喜一憂

いっきいちゆう

now rejoicing, now worrying, swinging from joy to sorrow, glad and sad by turns, alternating hope and fear, unable to put one's mind at ease

一芸一能

いちげいいちのう

(excelling in) one area or skill, (being skilled or gifted in) one certain area

一朝一夕

いっちょういっせき

in a day, in a brief space of time

一夫一妻

いっぷいっさい

monogamy

一汁一菜

いちじゅういっさい

one-plate meal, simple meal, austerity diet

一栄一落

rise and fall

一伍一什

いちごいちじゅう

full particulars, the whole story, from beginning to end

一世一代

いっせいちだい いっせいいちだい

once in a lifetime, the first and last occurrence (event, experience) of one's lifetime