Tangent: when looking up Mamoru Oshii I found an interview where he compared the work culture at Studio Ghibli to a communist dictatorship (“communism is when capitalism”), because people of the 1960s “Anpo generation” (like Miyazaki) have “no morals” when they believe their cause is just…
I didn’t look into the book, but what I can say is that 恋愛 ren’ai implies romantic love.
The book is apparently written by the same Mamoru “Studio Ghibli is like the Kremlin” Oshii, who is most well-known as the creater of Ghost in the Shell.
From that same interview I found, I didn’t get the impression however that he would just make shit up about him and try to ruin his career, he said it would be a loss if Miyazaki (and another Ghibli figure) stopped making films. The book itself, going by reviews, seems to be even-handed about his short experiences at Ghibli.