一も二も無く[ichimonimonaku] unhesitatingly
一言二言[hitokotofutakoto] a word or two
一石二鳥[issekinichou] killing two birds with one stone
一二に及ばず[ichininioyobazu] right away
一姫二太郎[ichihimenitarou] It's good to have a girl first and then a boy

うり二つ[urifutatsu] as alike as two melons (two peas in a pod)
黄道十二宮[koudoujuunikyuu] twelve signs of the zodiac
二度[futatabi] again
最小二乗法[saishounijouhou] least-squares method
三十二分音符[sanjuunibuonpu] 32nd note

御化け屋敷[obakeyashiki] haunted house
がっちり屋[gacchiriya] tightwad
ちんどん屋[chindonya] traditional Japanese band of sandwich board advertisers
はにかみ屋[hanikamiya] shy
ステーキ屋[suteekiya] steak house

ダフ屋[dafuya] (ticket) scalper ("dafu" is "fuda" backwards)
パン屋[panya] bakery
レコード屋[rekoodoya] record shop
握り屋[nigiriya] miser
井戸屋形[idoyakata] well roof

位階[ikai] court rank
位階勲等[ikaikuntou] court rank and honors
一階[ikkai] one floor
音階[onkai] musical scale
下層階級[kasoukaikyuu] proletariat

階下[kaika] lower floor
階級[kaikyuu] (social) class
階級章[kaikyuushou] rank insignia
階級闘争[kaikyuutousou] class struggle