7th of 12 games in the Epoch Wargame Electronics series. Each of the games features easy to learn rules (in Japanese), quick games that average about 30 minutes (not including setup), magnetic pieces on a set board, and an electronic dice-roller with 6 LED dots to work out the effects of combat.
As long as one player knows the rules, the other player does not need to know any Japanese in order to play the game.
This particular entry in the series centers around the Siege of Osaka in 1615 (in the summer!). The Summer Battle was actually a field battle-the siege of the Castle had taken place over the Winter of 1614-15. The official English title on the box is "The Sierge of Osaka in the Summer", but "Sierge" is a typo/mistranslation on their part.