Japan Airlines (JAL) plans to add another service between Tokyo's Haneda Airport and London Heathrow Airport beginning on Oct 29th. Flight JL041 will leave Haneda at 2:45 am, arriving in London at 6:25 am.
Meanwhile flight JL042 leaves London at 9:30 am, arriving in Haneda 6:25am the following day.
All users of the JL041 flight will be entitled to free use of the Heiwajima Spa (20 minutes by bus from Haneda, reservations through the JAL website is necessary) and the Sakura Lounge at Haneda. This includes Economy Class passengers.
JAL already offers two daily flights between Haneda and London (including a codeshare with British Airways) and also daily flights between Tokyo's Narita Airport and Heathrow.