diff --git a/system/inventory.go b/system/inventory.go
new file mode 100644
index 0000000..71db103
--- /dev/null
+++ b/system/inventory.go
@@ -0,0 +1,172 @@
+package system
+
+import (
+	"image/color"
+	"log/slog"
+	"math"
+
+	"github.com/hajimehoshi/ebiten/v2"
+	"github.com/hajimehoshi/ebiten/v2/inpututil"
+	"github.com/kensonjohnson/roguelike-game-go/internal/colors"
+	"github.com/kensonjohnson/roguelike-game-go/internal/config"
+	"github.com/yohamta/donburi/ecs"
+)
+
+type inventoryUi struct {
+	open bool
+}
+
+var InventoryUI = inventoryUi{open: false}
+
+func (i *inventoryUi) Update(ecs *ecs.ECS) {
+	if !i.open {
+		return
+	}
+
+	if inpututil.IsKeyJustPressed(ebiten.KeyI) || inpututil.IsKeyJustPressed(ebiten.KeyEscape) {
+		slog.Debug("Close Inventory")
+		Turn.TurnState = PlayerTurn
+		i.open = false
+	}
+}
+
+func (i *inventoryUi) Draw(ecs *ecs.ECS, screen *ebiten.Image) {
+	if !i.open {
+		return
+	}
+	image := makeBox(
+		(15)*config.TileWidth,
+		(8)*config.TileHeight,
+		colors.SlateGray,
+		colors.Black,
+	)
+	options := &ebiten.DrawImageOptions{}
+	options.GeoM.Reset()
+	options.GeoM.Translate(float64(5*config.TileWidth), float64(5*config.TileHeight))
+	screen.DrawImage(image, options)
+
+	image = makeBox(
+		(15)*config.TileWidth,
+		(5)*config.TileHeight,
+		colors.White,
+		colors.Transparent,
+	)
+	options.GeoM.Reset()
+	options.GeoM.Translate(float64(5*config.TileWidth), float64(15*config.TileHeight))
+	screen.DrawImage(image, options)
+
+	image = makeBox(
+		(15)*config.TileWidth,
+		(8)*config.TileHeight,
+		colors.Peru,
+		colors.SlateGray,
+	)
+	options.GeoM.Reset()
+	options.GeoM.Translate(float64(5*config.TileWidth), float64(25*config.TileHeight))
+	screen.DrawImage(image, options)
+}
+
+func (i *inventoryUi) Open() {
+	i.open = true
+}
+func (i *inventoryUi) Close() {
+	i.open = false
+}
+
+// TODO: Refactor to a proper place, probably internal
+// TODO: Allow for corner variants
+// w and h are pixel values
+func makeBox(w, h int, border, fill color.RGBA) *ebiten.Image {
+
+	image := ebiten.NewImage(w, h)
+	corner := makeCornerImage(border, fill)
+	size := corner.Bounds().Size()
+	options := &ebiten.DrawImageOptions{}
+
+	// NW
+	image.DrawImage(corner, options)
+
+	// NE
+	options.GeoM.Rotate(degreesToRadians(90))
+	options.GeoM.Translate(float64(w), 0)
+	image.DrawImage(corner, options)
+
+	// SE
+	options.GeoM.Reset()
+	options.GeoM.Rotate(degreesToRadians(180))
+	options.GeoM.Translate(float64(w), float64(h))
+	image.DrawImage(corner, options)
+
+	// SW
+	options.GeoM.Reset()
+	options.GeoM.Rotate(degreesToRadians(270))
+	options.GeoM.Translate(0, float64(h))
+	image.DrawImage(corner, options)
+
+	// Draw top and bottom lines, plus fill
+	line := ebiten.NewImage(w-(size.X*2), 1)
+	line.Fill(border)
+	for i := 0; i < size.Y; i++ {
+		if i == 4 {
+			line.Fill(fill)
+		}
+		options.GeoM.Reset()
+		options.GeoM.Translate(float64(size.X), float64(i))
+		image.DrawImage(line, options)
+		options.GeoM.Translate(0, float64(h-(i*2)-1))
+		image.DrawImage(line, options)
+	}
+
+	// Draw vertical lines and fill
+	line = ebiten.NewImage(w, h-(size.Y*2))
+	line.Fill(fill)
+	ends := ebiten.NewImage(4, h-(size.Y*2))
+	ends.Fill(border)
+	options.GeoM.Reset()
+	options.GeoM.Translate(float64(w-4), 0)
+	line.DrawImage(ends, options)
+	options.GeoM.Reset()
+	line.DrawImage(ends, options)
+	options.GeoM.Translate(0, float64(size.Y))
+	image.DrawImage(line, options)
+
+	return image
+}
+
+func makeCornerImage(border, fill color.RGBA) *ebiten.Image {
+	image := ebiten.NewImage(32, 32)
+	block := ebiten.NewImage(4, 4)
+	options := &ebiten.DrawImageOptions{}
+	for y, row := range cornerShape {
+		for x, value := range row {
+			options.GeoM.Reset()
+			options.GeoM.Translate(float64(x*4), float64(y*4))
+			switch value {
+			case -1:
+				continue
+			case 0:
+				block.Fill(border)
+			case 1:
+				block.Fill(fill)
+			}
+			image.DrawImage(block, options)
+		}
+	}
+
+	return image
+}
+
+func degreesToRadians(degrees int) float64 {
+	return float64(degrees) * math.Pi / 180
+}
+
+var cornerShape = [][]int8{
+	{0, 0, 0, 0, 0, -1, 0, 0},
+	{0, 1, 1, 1, 0, -1, 0, 1},
+	{0, 1, 1, 1, 0, 0, 0, 1},
+	{0, 1, 1, 1, 0, 1, 1, 1},
+	{0, 0, 0, 0, 0, 1, 1, 1},
+	{-1, -1, 0, 1, 1, 1, 1, 1},
+	{0, 0, 0, 1, 1, 1, 1, 1},
+	{0, 1, 1, 1, 1, 1, 1, 1},
+}