Kagawa attended Naniwa Shogyo High School in Osaka and was drafted by his hometown Hawks in the fall of 1979. Looking at the Hawks fielding stats during his career, it looks like he was mostly a backup catcher - another player had more games catching for the Hawks for every year except 1983 and 1985. 1983 was clearly Kagawa's best season - he hit .313 with 15 home runs. He was named to the Pacific League's Best Nine and made the All Star team that year. He also made the All Star team in 1984 despite the fact that his batting average plummeted almost 100 points to .215.
From what I can gather from the translation of his Japanese Wikipedia page, his weight was an issue throughout his career. His height and weight in his rookie year of 1980 was 5'7" and 216 pounds but (again referencing his Japanese Wikipedia page) he was popular enough that "he did not refuse the invitation of the meal from the parties". His weight reportedly ballooned to 286 and ultimately led to his release by the Hawks after the 1989 season. At 27, he was done as a player.
Here's some cards from during his career where you can see the weight gain.
|1980 Calbee #205|
|1980 Calbee Large #43|
|1983 Calbee #183|
|1985 Calbee #3|
|1998 BBM Hawks #FD76|
Here's a couple pieces of trivia regarding Kagawa. His battery mate in high school was Kazuhiko Ushijima, who would go on to play for the Dragons and Marines from 1980 to 1993. BBM devoted a card in last year's All Star Memories 80's set to the matchup between the two of them in the second game of the 1983 All Star series:
|2013 BBM All Star Memories 80's #82|
|1999 BBM Lions #SL29|