Originally Posted by AngelusM

This is how my experience went in december: after leaving the aircraft, crew directed us to the bus on the airside. Just after leaving the finger, went down an elevator and waited for the bus. No need to leave the safe area. There was a waiting room with very few people and a TV showing the next transfer buses. The process of waiting the bus + boarding the bus + arriving at T3 took us 15 minutes. When you arrive at T3, you will have to go through security again, but there was a specific line for business class. The line eventually merges with the economy class lines, so it's kind like a "shortcut". Security in Haneda was smooth in my experience. 1h15min should be enough for you, but there's not much time to spare and spend on lounges and shopping really. I had 1h50min of connection, but the process was so smooth and I could enjoy some shopping and lounge area. My Lufthansa flight got delayed some 30min too. Also, boarding a plane in Haneda (and in all Japan really) was the most peaceful and organized boarding ever. No stress at all. You should be fine.