Watanabe had qualified ninth for the snow-cancelled
Brands Hatch round, then lined up eleventh on the grid after a damp qualifying session at
Thruxton.
Those performances compare favourably with that of countryman Ryuichi Kiyonari, the future double BSB champion having qualified 19th and 18th respectively during his first visits to Brands Hatch and Thruxton in 2004.
But unfortunately for Watanabe - and unlike current Ten Kate Honda WSBK rider Kiyonari - 'Atsu' went backwards on race day, crossing the chequered flag 17th and 14th during the first ever all-Pirelli BSB event.
"The result is very bad," Watanabe said afterwards. "I'm not happy. I could not keep my ninth position."
But Valentine felt the BSB rookie was being a little hard on himself.
"Atsu is doing a great job," he declared. "I keep telling him to set his goals nice and realistic. Forget about trying to be in the top three and just keep setting achievable goals. He's going faster every time out. We've been looking at some data from when Kiyo first came over here and at both this circuit and Brands Hatch Atsu has been quicker."
Kiyonari finished 13th and eighth at his first Thruxton visit, which was round six of the 2004 series. The HM Plant Honda rider's BSB debut was earlier in the year at
Silverstone, where he qualified fourth and finished an excellent second in both races.
BSB 2008 now heads for
Oulton Park on May 3-5, where Watanabe will again be faced with learning a very 'British' circuit.
"Oulton Park is going to be a difficult one for Atsu," warned Valentine. "Another new circuit, very undulating and a lot of scenery quite close to the track. He's going to have another steep learning curve, but we'll be there before the meeting with John Reynolds on Superstock bikes so he can familiarise himself with the track."
Watanabe's team-mate, Tom Sykes, finished sixth and eighth during his Rizla Suzuki BSB debut.
