The Brave Blossoms are the current Asian rugby champions but have a record of just one win and a draw from their previous six World Cup tournaments, with 18 defeats.
Japan are in Pool A in New Zealand and will play the hosts, France, Tonga and Canada.
"I think if we can get there and play incredibly competitive games against France and New Zealand, and then play Tonga and Canada, we will show the world how much Japanese rugby has improved," the former All Blacks star said.
Months after Kirwan took the helm, he helped Japan end a 13-match World Cup losing streak with a draw against Canada in the 2007 event.
Japan are currently ranked 13th in the world, above Canada at 14th and Tonga at 15th. France are ranked fourth with New Zealand first.
Kirwan said that Japan, who will be captained by Takashi Kikutani, have "improved a lot overall. I think this team compared to four years ago is much more complete. We have a good combination and we are stronger and faster."
The squad contains a total of 10 foreign imports, including New Zealand-born fly-half James Arlidge and full-back Shaun Webb, as well as players from Tonga, Australia and Samoa.
"We need to use the foreign players to help our country get better," Kirwan added.
"I'm happy with the side, it's a sort of stage four. We've been working for the last four years to put the team together and understand how we want to play. The team is very familiar with each other with a good mix of youth and experience."
Japan 30-man squad: Forwards (16): Hisateru Hirashima (Kobe Steel Kobelco Steelers) Naoki Kawamata (Panasonic Wild Knights), Yusuke Aoki (Suntory Sungoliath), Shota Horie (Panasonic Wild Knights), Hiroki Yuhara (Toshiba Brave Lupus), Kensuke Hatakeyama (Suntory Sungoliath), Nozomu Fujita (Honda Heat), Hitoshi Ono (Toshiba Brave Lupus), Toshizumi Kitagawa (Toyota Verblitz), Luke Thompson (Kintetsu Liners), Justin Ives (Panasonic Wild Knights), Takashi Kikutani (Toyota Verblitz), Michael Leitch (Toshiba Brave Lupus), Sione Vatuvei (Panasonic Wild Knights), Ryukoliniasi Holani (Panasonic Wild Knights), Itaru Taniguchi (Kobe Steel Kobelco Steelers).
Backs (14): Fumiaki Tanaka (Panasonic Wild Knights), Tomoki Yoshida (Toshiba Brave Lupus), Atsushi Hiwasa (Suntory Sungoliath), James Arlidge (Nottingham), Murray Williams (Toyota Industries Shuttles), Yuta Imamura (Kobe Steel Kobelco Steelers), Ryan Nicholas (Suntory Sungoliath), Koji Taira (Suntory Sungoliath), Alisi Tupuailai (Canon Eagles), Hirotoki Onozawa (Suntory Sungoliath), Kosuke Endo (Toyota Verblitz), Takehisa Usuzuki (Toshiba Brave Lupus), Shaun Webb (Coca-Cola West Red), Taihei Ueda (Honda Heat).
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