I assume you are looking at this page:
https://www.city.taito.lg.jp/event/kanko/asakusayabusame.htmlOr this:
https://www.city.taito.lg.jp/bunka_kanko/other/yabusame40.html(The page with more details about ticket sales)
The event comes in 2 parts:
- Kusajishi (stationery archery, so to say), from 11:45- 12:45, you can watch at Sanyabori Hiroba in Sumida Park. (THis is completely free, no ticket sold at all.)
The location, Sanyabori Hiroba, is the open green space to the south of Taito Riverside Sports Centerfs outdoor pool, as I see on my google map.
- Yabusame (horse archery), from 13 - 14:30. You can watch from inside the specially set up area in Sumida Park. This area stretches from Sumida River Walk up till Kototoi bashi bridge.. (There will be tickets sold for some specific viewing areas; you donft have to have a ticket.)
On the second URL I provided, you scroll down a bit and then youfll be able to see a complicated map - this is the area of the Sumida park between Sumida River Walk and Kototoi-bashi Bridge. The area outlined in red line will be off limits unless you have a ticket. The three rhombus-shaped orange markers are the locations of the targets that the archers will aim for.
The rectangles - A (green), B (yellow), and C (pink) are the viewing areas for which tickets are sold. They also marked the entrances to those areas (too complicated to explain here).
Ticket sales: 3000 yen per seat - 300 seats in area A and 420 seats in area C. (B seems to be reserved for those in wheelchairs.)
THere is a website for advance ticket purchase (but they will snail mail you the tickets in April so that would have to be in Japan, I assume), or in person at the Asakusa Cultural Center in Asakusa, or at Taito Ward (city) hall.