Kiyo......speaking the Mother tounge where IJN Yamato was built, you may have knowledge as to why the Teak planked decking was not extended to the stern Quarter Deck, or the Forepeak Deck?
My only knowledge of a comparable Ship is BB63 the Missouri, where her decking extended to both extremities Fwd & Aft....I walked the length of her & confirm the Teak decking was in 1987, kept in superb condition
From images, it appears that the Royal Navy vessels of somewhat similar or and earlier vintage also had the Teak decking to both extremities
Derek