"You've reached Mamoru Chiba. I'm unavailable right now. Please leave a message."
August 3rd
4:36 PM
Usako-love
"Hey, Mamo, it's Usako! Oh, wait, you know that. You have my name in your phone—at least I hope you do, or you're in trouble. Like, sleeping on the couch trouble—anyway, and you know my voice. So, I just got off work. I should be home soon. I'm getting in my car right now. I'm so excited to see you. Happy birthday! I love you!"
August 3rd
10:58 PM
Furuhata, Motoki
"Hey, Mamoru . . . . I heard about Usagi. I am so sorry. I'll come by tomorrow. If you need anything, tell me."
August 4th
12:07 AM
Tsukino, Kenji
"We just got home and got your message. What's going on? Did something happen to Usagi? Answer your phone, boy!"
August 3rd
4:36 PM
Usako-love
"Hey, Mamo, it's Usako! Oh, wait, you know that. You have my name in your phone—at least I hope you do, or you're in trouble. Like, sleeping on the couch trouble—anyway, and you know my voice. So, I just got off work. I should be home soon. I'm getting in my car right now. I'm so excited to see you. Happy Birthday! I love you!"
August 4th
8:21 AM
Aino, Minako
"I know you're probably . . . um. Mamoru, please call back and tell us which room Usagi is in. I'm out here with Kai, Makoto, and Naoki. Rei, Jiyuu, and Seiki are on their way. Ami is already here on shift. Have you seen her yet? Anyway, please answer, Mamoru!"
August 17th
7:29 PM
Furuhata, Reika
"Hey, Mamoru. Um, we heard about Usagi. . . . Bye!"
August 19th
10:58 AM
Tsukino, Kenji
"You . . . you lost your wife. I lost my daughter. Mamoru . . . don't blame yourself. Usagi was driving and I hate to say it, but she's rather careless. The other driver was drunk. You couldn't do anything. I know it's tough, but you have to get over it. Usagi would hate to see you like this."
August 3rd
4:36 PM
Usako-love
"Hey, Mamo, it's Usako! Oh, wait, you know that. You have my name in your phone—at least I hope you do, or you're in trouble. Like, sleeping on the couch trouble—anyway, and you know my voice. So, I just got off work. I should be home soon. I'm getting in my car now. I'm so excited to see you. Happy Birthday! I love you!"
August 19th
6:45 PM
Tsukino, Ikuko
"Mamoru, please don't sit there all alone. You're still family, even if . . . if . . . . Oh, please come. We all need each other right now."
August 24th
11:18 AM
Misuke, Kai
"I know you've locked yourself in your apartment. You need to get out."
June 29th
2:49 AM
Usako-love
"Hi! Probably not the best time to call, but I wanted to say good night . . . even though it's morning and I really should be asleep already. I know you probably have a surgery but call back if you can. I miss you, Mamo. I want to spend some time curled up together. Anyway . . . I love you so much. I can't wait until your shift ends. Don't forget; we're going it for my birthday tomorrow."
August 24th
5:24 PM
Tsubasa, Naoki
"We're all at the arcade. Meet up with us. Kai told us that you haven't been answering him. Mamoru, you need to at least come outside."
December 25th
3:47 PM
Usako-love
"Merry Christmas! It's cold here. Can you believe it, honey? In three months, we'll be married! I'm so excited. Well, I know I'll see you tonight for Christmas, but I just needed to talk to you. Call me back if you can! I love you!"
August 3rd
4:36 PM
Usako-love
"Hey, Mamo, it's Usako! Oh, wait, you know that. You have my name in your phone—at least I hope you do, or you're in trouble. Like, sleeping on the couch trouble—anyway, and you know my voice. So, I just got off work. I should be home soon. I'm getting in my car now. I'm so excited to see you. Happy Birthday! I love you!"
August 29th
9:53 AM
Hijiri, Ami
"Hi, Mamoru. I wanted to give you the benefit of the doubt or at least let you realize it yourself, but it's been such a long time. I think you're depressed. You need to go to a counselor. Please believe me. You're our friend. Usagi would want you to be happy."
August 30th
4:56 AM
Hijiri, Seiki
"Get out of your house and go see a counselor. Ami is crying because she can't get through to you. You're worrying everyone. You need to go outside for more than work and food."
September 6th
7:09 AM
Tsukino, Shingo
"Mamoru, my sister did everything to make people happy. She didn't want to die, and if she had, she wouldn't have because it hurts too many people. Get better for her sake. Wherever she is, I bet you're kill—"
February 14th
12:40 PM
Usako-love
"Happy Valentine's Day! I love you! I love you! I love you! Hurry home and come to the bedroom. I love you!"
August 3rd
4:36 PM
Usako-love
"Hey, Mamo, it's Usako! Oh, wait, you know that. You have my name in your phone—at least I hope you do, or you're in trouble. Like, sleeping on the couch trouble—anyway, and you know my voice. So, I just got off work. I should be home soon. I'm getting in my car now. I'm so excited to see you. Happy Birthday! I love you!"
August 3rd
4:36 PM
Usako-love
"Hey, Mamo, it's Usako! Oh, wait, you know that. You have my name in your phone—at least I hope you do, or you're in trouble. Like, sleeping on the couch trouble—anyway, and you know my voice. So, I just got off work. I should be home soon. I'm getting in my car now. I'm so excited to see you. Happy Birthday! I love you!"
September 15th
2:20 PM
Kino, Makoto
"Hi. I know we've been ignoring you. Sorry. Um, we- sorry. But it's been over a month. Please come outside."
September 17th
8:45 PM
Tsukino, Ikuko
"Mamoru, please know that you can come over any time you need. But we can't keep calling anymore. We're moving on and you need to too. Mamoru, you are my second son. But we can't keep Usagi's spirit tethered to the world. Let her go."
September 21st
3:33 PM
Hino, Rei
"You forgot your jacket here. I'm glad you came out. Usagi would be happy."
September 26th
11:03 PM
Misuke, Kai
"You are some piece of work, Mamoru Chiba. You make everyone think that you're okay and suddenly go right back to moping around. I know you loved Usagi. But she's dead. You need to move on. You can't live your life this way. You looked like you were starving.
"Mamoru, she's gone. Accept it."
August 3rd
4:36 PM
Usako-love
"Hey, Mamo, it's Usako! Oh, wait, you know that. You have my name in your phone—at least I hope you do, or you're in trouble. Like, sleeping on the couch trouble—anyway, and you know my voice. So, I just got off work. I should be home soon. I'm getting in my car now. I'm so excited to see you. Happy Birthday! I love you!"
August 3rd
4:36 PM
Usako-love
"Hey, Mamo, it's Usako! Oh, wait, you know that. You have my name in your phone—at least I hope you do, or you're in trouble. Like, sleeping on the couch trouble—anyway, and you know my voice. So, I just got off work. I should be home soon. I'm getting in my car now. I'm so excited to see you. Happy Birthday! I love you!"
July 13th
6:04 PM
Usako-love
"Get home, mister! I have a surprise. A huge surprise! Well, not yet. Right now it's just a little bump. Not even that. Oops! You probably figured it out by now. It doesn't matter. I'm pregnant! I can't believe we're going to be parents. This is so exciting! I love you, Mamo!"
September 30th
10:05 AM
Tsukino, Shingo
"She's dead."
"You've reached Mamoru Chiba. Don't leave a message. Stop calling. I don't want any help. My pregnant wife died. Leave me alone."
This is probably a bit depressing but I had this idea and needed to use it. Sadly, this is the first time I've ever mentioned the Shitennou in the modern world or given them other names. I have more ideas to add them in, but none in this universe. It might be surprising, but I actually don't like hurting Mamoru. I'm fairly sure the names are straight forward, but ask me if you need to.
The implied story of this one-shot is that Usagi was driving home after work and a drunk driver crashed into her. Add in the other details you've picked up.