right in the midst of; right at the height of
今は受験の真っ只中だ。
It's currently the height of exam season.
桜が真っ只中の街を散歩した。
I strolled through a city at the height of cherry blossom season.
記者は紛争の真っ只中で取材を続けた。
The reporter continued reporting from the midst of the conflict.