noun
great enthusiasm; very keen; in high spirits
Describes a state of being very eager, excited, or in a great mood about something. Often used when someone is really looking forward to an event or activity.
彼は明日の旅行に大乗り気だ。
He is really excited about tomorrow's trip.
彼女は新しいプロジェクトに大乗り気で、早速準備を始めた。
She was very enthusiastic about the new project and started preparing right away.