Misa's Pure Love Memorial is a section in Ryuk's Human Observation Journal featured in Death Note 13: How to Read. The caption description reads, "'I'll do anything for Light!' Misa will often yell out serious things like that without a care in the world. Let's take a look at this diary, which chronicles her burning passion." Ryuk comments on this, saying, "This diary really pisses me off..."
The description of the diary that Misa wrote (and Ryuk has somehow gotten ahold of) is entitled, "Me and Light's Love Love Diary! ♡" and reads, "This is Misa's super special diary, where I've recorded the journey from when I first had my dramatic encounter with Light, all the way up to marriage [squeal]! Looking back on everything now, a lot of stuff sure happened."
The contents of Misa's diary include sections entitled "Love Memories." These include descriptions of scenarios, pictures of what occurred, and commentary from Light. There is also an additional section regarding other girls pining for Light's affection.
"Love Memory 1: Kira became my boyfriend" Edit
Description: "When I met Light at Aoyama, Misa's heart was struck by Cupid's arrow! I think Light felt the same way, too, because he went out with me in no time!"
Image 1: Light reading the Second Kira's schedule
Image title: "I sent a love letter!"
Caption: "I think he noticed how much passion I put into it!"
Image 2: Misa finding out Light's name through the power of her Shinigami Eyes
Image title: "I got his name thanks to the Shinigami Eyes!"
Caption: "Name confirmed with the Shinigami Eyes. What a cool name..."
Image 3: Misa asking Light to let her be his girlfriend shortly after meeting him
Image title: "My pushy proposal"
Caption: "I couldn't wait any longer, so I went to his house. Would he be interested in me as his girlfriend?"
Light's comment: "She's like a stalker..."
"Love Memory 2: I dazzled Light with my array of outfits!" Edit
Description: "I put on tons of outfits to show Light a good time! I thought he'd be happy, but he was always so quiet. Light, you really have to open up!"
Image 1: Misa disguised as a schoolgirl
Caption: "Schoolgirl uniform's a must! This had to hit the strike zone!"
Image 2: Misa disguised as Nori, a nurse
Caption: "I think this really appealed to Light's more serious side!"
Image 3: Misa wearing lingerie
Caption: "This was my best shot! What do you think, Light?"
Light's comment: "Huh? Oh, yeah."
"Love Memory 3: I'll risk my life to save you!" Edit
Description: "Because I'm Kira's girlfriend, of course I helped with creating the new world! Misa's a helpful girl!"
Image 1: Light looking at Misa, who is seeing L's real name with her Shinigami Eyes
Image title: "I saw L's name!"
Caption: "Misa's greatest feat! At least, it should have been. Sorry, Light..."
Image 2: Misa running towards Light with news on Kyosuke Higuchi
Image title: "Got a confession out of Higuchi!"
Caption: "Got evidence against Yotsuba Kira! Was I a help to Light again today?"
Image 3: Misa on a laptop, searching through pictures of mafia members and looking at their real names with her Shinigami Eyes
Image title: "Checking up on the mafia!"
Caption: "I spent a lot of late nights looking for the owner of the Death Note for Light. There might've been some times I felt overwhelmed."
Light's comment: "Hmm? Yeah, good work."
"Love Memory 4: Light and I, together at long last!" Edit
Description: "Finally, Light proposed to me! Now I can go back to being a regular girl, and live happily ever after with Light!"
Image 1: Light walking into his bedroom, where Misa is lying on the bed
Image title: "Roommates"
Caption: "For a while, Light was so busy that we hardly ever saw each other. But it's okay, because I know how Light feels."
Image 2: Misa asking Light if, by asking her to quit her job, he is proposing marriage, to which he hastily agrees
Image title: "And then... ...the proposal!"
Caption: "Light asked me to quit my job as an actress. Does this mean he wants to be with me every day?!"
Misa crushes all of her rivals!" Edit
Description: "The meddlesome girls I need to keep an eye out for. Light already has a girlfriend, so get a clue and give up!"
Image 1: person in question
Image title: "Kiyomi Takada"
Caption: "She only met Light at work, so Misa wins!"
Image 2: person in question
Image title: "Yuri"
Caption: "Misa wins for having a more mature charm!"
Light's comment: "Damn it!"
Finally, there is a picture of Misa hugging Light, who is silently pondering whether or not he should kill Misa. An added word bubble coming out of Misa's mouth says, "Misa's going to be so happy!" To the left of this is Ryuk, tilting his head in confusion and saying, "Huh? But he's dead."