Circular 7-9 day hike in Northern Alps

Hi there I really enjoyed the piece on the Kamikochi - Yarigatake - Okuhotaka-dake Circuit. I am planning on visiting Japan in May 2023 with my climbing partner. We would like to do a longer multi-day peak bagging adventure of c7-9 days , perhaps heading further north to Washiba Dake then returning on the eastern ridge that takes in Tubakuro Dake, Daitejyo Dake,Jonen Dake and Chogatake.
Does anyone have any suggestions on an itinerary/advice? I see we'd need to cross Takase river to access the eastern peaks. Where would be the best place to do that?
Alternatively we could do a linear hike ending somewhere near Kurobe Dam - perhaps after climbing Tateyama and Turugi Dake (though I see we'd have to do that after 15 May) and then take public transport back to Kamikochi.
We are both experienced alpinists (I am British but now living in South Africa) and will bring crampons, ice-axes and a rope in case conditions require.