since there are no subtitles i am forced to notice just how easy to understand kaikis voice is, he speaks so clearly and well-paced, and thats about what i get from this video
When Karen is explaining her name, she said "カレンだKaren da", (meaning "I'm Karen") which in japanese is really close to the word "カレンダーKarendaa" that means calender. And the kanji for his brother's name Koyomi has the meaning of calender. Nisio Isin for you right there.