The following furniture will change with the season.

  • Do note that those changes are arbitrary and may not happen at the same time each year, if at all.

Chair+Desk

Chabudai Set

The "Chabudai Set" (ちゃぶ台セット) will change depending on the season: During the saury season, food will change depending on the secretary (see here)).

Season Look Picture
Normal Fish  
Saury Saury   

Admiral's Mahjong Table

The "Admiral's Mahjong Table" (提督の麻雀卓) will change depending on the season:

Season Look Picture
Winter Snow patterns kotatsu futon
(Clicking on the cat's tail produces a reaction)
 
Setubun Setsubun-themed kotatsu futon
(Clicking on the cat's tail produces a reaction)
 
Summer No kotatsu futon & simple sake  
Fall No kotatsu futon & twin sake  

Hot Spring Hinoki Bath

The "Hot Spring Hinoki Bath" (温泉檜風呂) will change depending on the season:

Season Look Picture
Spring Sakura & tea    
Rainy season Hydrangea  
Fall Red maple leafs & tea / susuki & sake    
2021 Sake  
? Blanc  

Hot Spring Stone Bath

The "Hot Spring Stone Bath" (温泉岩風呂) will change depending on the season:

Season Look Picture
Spring Sakura /& sake   
Rainy season Hydrangea  
Summer Sunflowers  
Fall Red maple leafs /& sake / susuki    
Winter Nanten & mikans  
? Sake  

Admiral's New Year's Big Splish-Up

The "Admiral's New Year's Big Splish-Up" (年末年始の提督大奮発) will change depending on the season:

Season Look Picture
01/01-01/07 Ozoni  
01/07-12/26 Rice porridge with seven herbs  
12/27-12/31 New Year's Eve soba noodles  

Café Table Set

The "Café Table Set" (Caféテーブルセット) will change depending on the season:

Season Look Picture
Normal Pancakes  
Zuiun Festival Pancakes & Zuiun  
White Day ? 150px
Halloween Pumpkin cakes  
Christmas Xmas cakes  
Autumn Mont Blanc  
? ? 150px

Coastal Defense Ships' General-purpose Circular Desk

The "Coastal Defense Ships' General-purpose Circular Desk" (海防艦の汎用円形机) will change depending on the season:

Season Look Picture
New Year Ozoni, Kadomatsu, and ink writing  
Setsubun? ?  
Valentine's Day Chocolate making  
White Day White Day 150px
Autumn Chestnuts cracking and writing/drawing  
Saury Saury flag and food  
Christmas Wmass foods and decorations  
New Year's Eve New year soba  

Mikans and a Custom-made Naval Base Chabudai Table

The "Mikans and a Custom-made Naval Base Chabudai Table" (蜜柑と特注鎮守府ちゃぶ台) will change depending on the season: During the New Year season, food will change depending on the secretary (see here)).

Season Look Picture
Spring/Summer Strawberies sweets  
Fall Green tea & fried rice?  
Saury & soup Saury  
Christmas Strawberies cake  
New Year New's year soba    

Admiral and Ooyodo Secretary Desk

The "Admiral and Ooyodo Secretary Desk" (提督と大淀秘書机) will change depending on the season:

Season Look Picture
Fall Cosmos & ? , mikans & tea  
Rainy Season Hydrangeas, cakes & tea  
? ? 150px

Admiral and 3rd Squadron Table

The "Admiral and 3rd Squadron Table" (提督と第三戦隊のテーブル) will change depending on the season:

Season Look Picture
Fall Kirishima's stuff & mikan cake  
Winter ? 150px
Spring ? 150px
Summer ? 150px

Windows+Curtains

Naval Base Counter Bar

The Naval Base Counter Bar's food will change depending on the season.

Mini Kadomatsu and Zodiac Window

The "Mini Kadomatsu and Zodiac Window" (ミニ門松と干支の窓) will change depending on the year:

Year Picture
Ox  
Tiger 200px
Rabbit  
Dragon  

Submarine Squadron Window

The "Submarine Squadron Window" (潜水艦隊の窓) will change depending on the season:

Season Look Picture
New Year ? & Kadomatsu  
Autumn Mapple leafs & chestnuts  
Summer Sunflowers & ice  
Setsubun ? & Setsubun beans  
? ? & rice porridge with seven herbs  
Christmas Poinsettia & Xmass decorations, cakes and gifts  
New Year's Eve New Year's Eve soba noodles  
? ?  
Saury ? & Saury flag  
? ? 200px

Haruna's White Window

The "Haruna's White Window" (榛名の白い窓) will change depending on the season:

Season Look Picture
Autumn Mapple leafs & ?  
? ? & coffee  
? ? 200px

Mainstay of Mainstay Seasonal Window

The "Mainstay of Mainstay Seasonal Window" (主力オブ主力な季節の窓) will change depending on the season:

Season Picture
Setsubun  
Autumn  
Fall  
200px

Decoration

Japanese Cherry Blossom Arrangement

The "Japanese Cherry Blossom Arrangement" (桜の和のアレンジメント) will change depending on the season:

Season Look Picture
03/23~03/25 Buds  
03/25~03/28 50% in bloom
(animated when clicked-on)
 
03/28~04/08 75% in bloom
(animated when clicked-on)
 
04/09~03/22 Full bloom
(animated when clicked-on)
 
04/9~?? Leafed cherry blossoms
(animated when clicked-on)
 
? Leafed  

Large Flower Arrangement

The "Large Flower Arrangement" (大型生花アレンジメント) will change depending on the season:

Season Look Picture
Winter Poinsettia, winter rose, sweet alyssum  
Rainy season Hydrangeas 100px
Summer Sunflowers  
Fall Dahlia, cosmos, bellflower, lady's mantle, kudzu, salvia  

7th Destroyer Squadron Personal Belongings Shelf

The "7th Destroyer Squadron Personal Belongings Shelf" (七駆の私物棚) will change depending on the season:

Season Look Picture
Autumn Sweet potatoes, autumn leafs, susukis  
Setsubun Setsubun beans, panel, and bag  
? ? 100px

Furniture+Shelf

Ship Girls' Umbrella Stand

The Ship Girls' Umbrella Stand's will have individual umbrellas removed depending on the flagship during the rainy season.