Dictionary / Vocabulary / 一気呵成
いっきかせい
finishing writing, work, etc. at a stroke (stretch); knocking something off without a break
Also written 一気かせい
彼、一気呵成に書き上げたと言ってたけど、この提案書、少し雑だね。
He said he dashed this proposal off in one sitting. It's pretty sloppy.